20L Solution Final Solution


 Washunegn Teka Zeleke
 25 days ago
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1 1. Which of the following numbers is different from the others? 7854, 8432, 3927, 5735, 9872 A B C D E Explanation: The correct answer is (A). In all the numbers, the last two digits are formed by multiplying the first two digits except In chemistry laboratory a student is given 20 liters solution which is 40 % salt. How much water shall he add to make the solution 32% salt. 40% Salt 32% Salt 20L Solution Final Solution A. 7L B. 5L C. 6L D. 8L Explanation: The correct answer is (B).
2 initially the % of salt = 40% = (Amount of salt) (Total solution) (Amount of salt) 100% = 100% (20L) Amount of salt = 8L; remember that the amount of salt not changed. In the final solution, the % of salt = 32% = Amount of water added = 5L (Amount of salt) 100% = (8L) 100% (Total solution) (20L + Amount of water added) 3. When I arrived at work at 8:00 AM my watch was working correctly, but it began to lose 12 minutes per hour. When I watch it to leave the work, it is now showing the time as PM, but it stopped completely four hours ago. What is the correct time? A. 4:00 PM B. 4:30 PM C. 5:30 PM D. 5:00 PM Explanation: The correct answer is (D). My Watch 8:00AM 8:48AM 9:36AM 10:24AM 11:12AM 12:00PM Accurate Time 8:00AM 9:00AM 10:00AM 11:00AM 12:00PM 1:00PM Thus, the accurate time is 1:00PM + 4 hrs. = 5:00PM 4. The following pie charts show the data for COVID19 report provided by NY City Health as of May 13, 2020, and the result show 25 % of the people who have recovered were from West Region. It can be noted that the absolute number of deaths of patients in West Region is only 250 and which is the lowest number compared to the other regions. Then, from these data how many people are being treated in hospital in other regions without including the West Region? Total confirmed cases for the city is people. West Region South Region 26% 18% 20% COVID19 Confirmed 12,500 36% North Region East Region Death Being Treated in Hospitals 26% COVID19 Confirmed 12,500 34% 40% Recovered
3 A B C D Explanation: The correct answer is (D). COVID19 confirmed case in West Region = = People who have recovered = 40 12,500 = People who have recovered in West Region = = People being treated in Hospitals = = People being treated in Hospitals in West Region = confirmed case in West Region recovered in West Region deaths of patients in West Region = = 750 Thus, people being treated in Hospital in other regions not including West Region = People being treated in Hospitals People being treated in Hospitals in West Region = = John is older than Marta and younger than Robel. Tom is younger than Robel and older than John. Then, which of the following statement is true? A. Marta is older than Tom. B. John is older than Tom. C. Tom is older than Marta. D. Marta is older than Robel Explanation: The correct answer is (C). (i)john is older than Marta { } {Tom is older than Marta} (A) is False and (C) is True (ii)tom is older than John {Tom is older than John} (B) is False (i) John is younger than Robel Robel is older than John { } {Robel is older than Marta} (ii) John is older than Marta (D) is False 6. The following six athletes qualified for Men's 100m final. The athletes take up a position with their hands just behind the line. Usain Bolt is positioned to the right of Justin Gatlin but is not positioned next to Asafa Powell. Asafa Powell is positioned next to Yohan Blake, who has Usain Bolt on his left side. Jimmy Vacout is positioned next to Akani
4 Simbine who is positioned furthest from Asafa Powell. Who is the athlete positioned to the right of Yohan Blake? A. Asafa Powell B. Justin Gatlin C. Usain Bolt D. Jimmy Vacout Explanation: The correct answer is (A). The position of the athletes is: Akani Simbine Jimmy Vacout Justin Gatlin Usain Bolt Yohan Blake Asafa Powell 7. A family is playing on their yard wooden balance scale. The mother with a baby on her hand together with her daughter climbed on the left side, and the father and the son climbed on the other side. At these positions shown below the scale become balanced. What is the weight of the baby? 48Kg 50Kg 15Kg 60Kg A. 5 Kg B. 6 Kg C. 4 Kg D. 4.5Kg Explanation: The correct answer is (B). 5(48 + Weight of baby) + 3(50) = 4(15) + 6(60)
5 Weight of baby = 6kg 8. The planets in our solar system never line up in one perfectly straight line. However, let us assume planet Venus takes two years to revolve once round the sun along its circular path, and planet Earth takes three years, when will they next both be in straight line with the sun? A. 4 years B. 6 years C. 3 year D. 2 years Earth Venus Sun Explanation: The correct answer is (C); (i)venus revolves half round the sun (180 0 ) After one year { (ii)earth revolves one third of full round of the sun (120 0 ) } (i)venus revolves once round the sun (360 0 ) After two years { (ii)earth revolves two third of full round of the sun (240 0 ) } After three years { (i)venus revolves one and half round the sun (5400 ) (ii)earth revolves one tghird round of the sun (360 0 ) } thus, three of them will be in straight line
6 9. Today, my sister is celebrating her birthday and she put the same number of candles on her cake as of her age. Since her birth, she has celebrated her birthday by putting same number of candles as of her age in each year. Up to now, all the birthday cake candles she has ever had 378 candles. How old is she now? A. 27 years B. 28 years C. 23 years D. 24 years Explanation: The correct answer is (A); Let say She is celebrating n years of age Sum of birthday Candles (S n ) = n year = 378 For an arthemetic secuense, S n = n ( a 1 + a n ) 2 Sum of birthday Candles = 378 = n ( 1 + n 2 ) n = 27 years 10. My father is 28 years older than me. Four years ago, his age was three times that of mine. How old is my dad? A. 33 years B. 36 years C. 42 years D. 46 years Explanation: The correct answer is (D); Now Age of father = 28 + Age of me Four Yers ago (Age of father 4) = 3(Age of me 4) (Age of father 4) = 3((Age of Father 28) 4) (Age of father 4) = 3((Age of Father 28) 4) Age of father = 46 years 11. From the students who took history exam, 75% of the students were boys. 25% of the girls and 50% of the boys passed the exam. The number of boys failed were 1176, find the number of girls who failed the exam.
7 A B. 588 C D. 882 Explanation: The correct answer is (B); Students who took history exam = Boys + Girls; Boys = (Students) = 3 4 (Students); Boys passed = (Boys) = 1 2 (3 4 (Students) = 3 8 (Students) ; Girls passed = (Girls) = 1 4 (1 4 (Students) = 1 16 (Students) ; Girls = (Students) = 1 4 (Students); Boys failed = 1176 = Boys Boys passed = 3 4 (Students) 3 8 (Students); Students = 3136 Girls failed = Girls Girls passed = 1 4 (Students) 1 16 (Students) = 3 16 (Students); Girls failed = persons were contacted to complete a project work in 50 days. Each person working 8 hours a day they have completed 1/5 of the work in 20 days. The contactor considered that it will not be completed if the work continues like this; and he decided to hire additional persons and now each person to work 12 hours per day. How many additional persons he must hire so that the project will be completed at the specified date? A. 250 B. 120 C. 210 D. 150 Explanation: The correct answer is (C); Part of the work completed = 1 (Total work); Remaining work = 4 (Total work) 5 5
8 Part of the work completed = (250persons) (8 hours day ) 20days = 1 (Total work) 5 Total work = 5 hours (250persons) (8 1 day ) 20days Remaining days to complete the work= = 30days Remaining work will be completed = (Npersons) (12 hours day ) 30days = 4 (Total work) 5 (Npersons) (12 hours day ) 30days = 4 ((Total work) 5 (Npersons) (12 hours day ) 30days = 4 5 [5 hours (250persons) (8 1 day ) 20days] Npersons = 480 Addional persons = = Firefighting Reservoir Water Tank has two water supply lines one is from municipality V1 and the other is from underground V2. When municipality valve V1 fully open it can fill the tank in 9 hours and alternatively underground valve V2 can fill the tank in 12 hours. When the consumption valve opened V3 it can empty the full tank in 15 hours. All the three valves are opened at the beginning. After 6 hours, the consumption valve V3 is closed. In total, how long will it take to make the tank full? V1 V2 V3 A. 7hrs. and 20 minutes. B. 8hrs and 30minutes
9 C. 8hr and 20minutes D. 7hrs and 12minutes Explanation: The correct answer is (D); Total volume of tank = V Liters, In one hour, Valve V1 can fill= V 9 ; Valve V2 can fill= V 12 ; and Valve V3 can empty = V 15 The volume filled in 6 hrs., = 6 [ V 9 + V 12 V 15 ] Liters Valve V3 is closed after 6hrs., then let say, the tank is filled after t hrs. The water filled in the tank after t hrs., = t [ V 9 + V 12 ] Liters = V 6 [V 9 + V 12 V 15 ] Liters t [ V 9 + V 12 ] = V 6 [V 9 + V 12 V 15 ] t[ ] = 180 6[ ] t[ ] = 1.2hrs. Thus, the total time required to fill the tank is = = 7.2 hrs. 14. Find the next number in the series 2, 7, 17, 37, 77, 157, 317,? A. 537 B. 517 C. 617 D. 637 Explanation: The correct answer is (D); In order to get the next number in the series the first number multiplied by two and plus thee. 2(2) + 3, 7(2) + 3, 17(2) + 3, 37(2) + 3, 77(2) + 3, 157(2) + 3, 317(2) (2) + 3 = Introducing a man, a woman said: He is the son of the man who is the father of the wife of my father. How is the man related to the woman? A. Uncle B. Cousin C. Brother
10 D. Father Explanation: The correct answer is (A); The man is the uncle of the woman. Woman = I My father wife My mother; My mother father My grandfather My grandfather son My mother brother; My mother brother My Uncle Grand Father Father Mother Uncle Woman 16. A woman wants to jog along the road. When she went out from her house, she was facing South. Immediately she turned left and started jogging until 3km; then she turned left again and jogged 1.5km; then she turned right and jogged 1.5km and then turning left jogged 3km. then she turned left again and jogged 9km. At this point, in which direction is she from her house? A. SouthEast B. NorthEast. C. NorthWest D. South West Explanation: The correct answer is (C); NorthWest
11 17. In presidential election, which was held on 17 September 2019, between Mr. Tamar and Mr. Meretz; Mr. Tamar won with 80% of the total valid votes. The total number of votes was counted to , but 3% of the votes were in valid. then how many numbers of valid votes that Mr. Meretz received? A B C D Explanation: The correct answer is (A); Total Vote = Valid Vote + Invalid Vote = Invalid Vote = 3 (150000) = Valid Vote = = Mr. Meretz Valid Vote = (Valid Vote ) = ( ) = At what time between 10 and 11 o'clock will the hands of a watch be together?
12 A min. past B C D min. past 10 min. past 10 min. past 10 Explanation: The correct answer is (B); The minute hand takes 60 minutes to move one complete cycle in 1 minute, the minute hand moves 1 division The hour hand takes 60 minutes to move from the given o clock to the next o clock 5 division in 1 minute, the hour hand moves 1 12 divisions Let say, after X minutes both minute hand and hour hand coincide between 10 and 11 o'clock The division moved by minute hand will be = x divisions; and hour hand = X 12 divisions Then subtracting the divisions; x divisions divisions formed by 10 o clock = X 12 divisions X divisions 50 divisions = X 12 divisions X = minutes 19. In refugees camp, there is food which can serve 160 children or 96 women. If 120 children have eaten their food, for how many women will be enough the remaining food?
13 A. 25 B. 30 C. 24 D. 20 Explanation: The correct answer is (C); Total Food (F) will be enough for 160 children; one child will eat = (F) Total Food (F) will be enough for 96 women; one woman will eat = 1 96 (F) Assume, the remaining food will be enough for N women Remaining food = N [ 1 96 (F)] = (F) 120 [ (F)] N [ 1 96 ] = 1 [ ] N = Today I received my salary and I spent 24% of it to buy new clothes and 18% of the remaining on buying fuel for my car. Then I paid for my lunch 192 dollars in the restaurant. If I left with 1500 dollars, how much did I pay for my car fuel? A. 342 dollars B. 240 dollars C. 320 dollars D. 350 dollars Explanation: The correct answer is (A); Total salary (S) The money spent to buy new clothes = (S) Now, remaining amount = (S) Money spent on fuel = [ (S)] Money spent for the food = 58 dollar
14 Total salary = spent to buy new clothes + spent on fuel + spent for the food + Remaing money on the hand S = (S) [ 76 (S)] + 58 dollar dollar 100 S = 0.24(S) (S) dollar (S) = 1558 dollar S = 2500 dollar Thus, money spent on fuel = 18 [ (S)] = [ 76 (2500 dollar)] = 342 dollars I had started a new startup business in small Business Administration and invested 5000$ for the whole year. I shared my idea to my friend, and 4 months later he joined me and invested 6000$. In the next year I invested 1000$ more and my friend withdrew 1000$ and at the end of two years I earned profit 2750$. If we distributed half of the total profit equally and rest in the capital ratio, how much total profit we got? A. 5500$ B. 6000$ C. 5000$ D. 4500$ Correct Ans:62900 Explanation: The correct answer is (C); I invested for the first year = 5000$ and for the next year = 5000$ $ = 6000$ My friend invested for 8 months = 70000$ and for the next year = 6000$ 1000$ = 5000$ The capital ratio is between me and my friend: [( ) + ( )]: [(6000 8) + ( )]: [ ]: [ ] 72: 48 3: 2 Assume the total profit (P) Half of the profit distributed equally 1 2 [1 P] for me, and [1 P] for my freind 2
15 Half of the profit distributed in the capital ratio 3 5 [1 P] for me, and [1 P] for my freind 2 At the end of two years my profit was 2750$ = 1 2 [1 2 P] [1 2 P] 2750$ = 1 4 [P] [P] P = 5000$ 22. Switch A turns lights L1 and L2 on/off or off/on Switch B turns lights L2 and L4 on/off or off/on Switch C turns lights L1 and L3 on/off or off/on Switch D turns lights L3 and L4 on/off or off/on Switches B, D, A and C are thrown in turn with the result that Figure 1 turns into Figure 2. Which switch does not work at all? Status L1 L2 L3 L4 ON OFF L1 L1 L2 L2 L3 L3 L4 L4
16 A. Switch A B. Switch B C. Switch C D. Switch D Explanation: The correct answer is (A); When we switched the switches sequentially as per the given sequence B D A C 1 st B turns lights L2 and L4 as shown below B1 to B2 starting from figure 1 status 2 nd D turns lights L3 and L4 as shown below D1 to D2 starting from figure 1 status or B2 3 rd A turns lights L1 and L2 as shown below A1 to A2 starting from figure 1 status or B2 4 th C turns lights L1 and L3 as shown below C1 to C2 starting from figure 1 status or A2 or D2 Status L1 L2 L3 L4 ON A1 C2 B2 A1 D2 C1 B1 D2 OFF A2 C1 B1 A2 D1 C2 B2 D1 Comparing the final result on the Lights A2, B2, C2, D2 with figure 2 results L1 C2 Switch A is not working L2 A2 Switch A is not working L3 C2 Switch C is working
17 L4 D2 Switch D is working Switch B is working 23. What day is three days after the day immediately following the day two days after the day three days before the day immediately after Wednesday? A. Saturday B. Sunday C. Tuesday D. Monday Explanation: The correct answer is (B); MONTUEWEDTHUFRISATSUN 24. The average of five consecutive even number is 30. Find the largest of these number A. 24 B. 30 C. 34 D. 26 Explanation: The correct answer is (C); Let the consecutive numbers: n, n + 2, n + 4, n + 6, n + 8 n + (n + 2) + (n + 4) + (n + 6) + (n + 8) Average = [ ] = n + 20 [ ] = 30 5 n = N2 is a threedigit number. If the number is divisible by 6, which of the following number can replace N? A. 4 B. 6 C. 3 D. 2 Explanation: The correct answer is (D); If the last digit of the number is even it is divisible by 2 If the sum of the digits is divisible by 3 it is divisible by 3
18 If the number is divisible by 2 and 3 it is divisible by 6 5N2 the last digit of the number is even is divisible by N + 2 = N + 7, if N=2 the sum of the digits will be 9 tit will be divisible by How many different sized circles appear below? A. 17 B. 18 C. 19 D. 16
19 Explanation: The correct answer is (B); = Newton is force, Kelvin is for what? A. Sound B. Frequency C. Temperature D. Energy Explanation: The correct answer is (C); Temperature 28. A car moved diagonally across a square field. Approximately, what was the percent saved by not driving along the sides? A. 30 B. 24 C. 14 D. 20 Explanation: The correct answer is (A); When he traveled diagonally, he covered x 1.4x When he traveled along the sides, he covered 2x; Saved distance = 2x 1.4x = 0.6x % Saved = 0.6x 2x 100 = 30 x x x 29. Today it is Friday. After 132 days, it will be A. Sunday B. Monday C. Friday D. Thursday
20 Explanation: The correct answer is (D); Each day of the week is repeated after 7 days. 132/7 = x 7 = 133, After 133 days it will be Friday 30. Half percent, written as a decimal, is A B C D. 0.2 After 132days it will be Thursday Explanation: The correct answer is (B); % = 0.5% = =