- Aptitude - Home
- Aptitude - Overview
- Quantitative Aptitude
Chain Rules - Online Quiz
Following quiz provides Multiple Choice Questions (MCQs) related to Chain Rules. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.
Q 1 - If 4/5th of a cistern is filled in 1 minute, how much more time will be required to fill the rest of it?
Answer : B
Explanation
Let the required time be x seconds. Part filled = 4/5, Remaining part = (1- 4/5 ) = 1/5. Less part to be filled , less is the time taken (direct) 4/5 :1/5 :: 60 : x ⇒ 4/5 * x = (1/5 * 60 ) = 12 ⇒ x= (12 * 5/4 ) = 15. Required time = 15 seconds.
Q 2 - 16 men can reap a field in 30 days . In how many days will 20 men reap the field?
Answer : B
Explanation
Let the required number of days be x. More men , less days (Indirect) 20 : 16 :: 30 : x⇒ 20x = (16 *30 ) ⇒ x = (16*30)/20 =24days.
Q 3 - 10 women can complete a piece of work in 8 days and 10 children take 12 days to complete it. How many days will 6 women and 3 children together take to complete the work?
Answer : C
Explanation
1 women can complete the work in ( 10 * 8) = 80 days. 1 child can complete the work in ( 10 * 12) = 120 days. 1 women 1 days work = 1/80, 1 child 1 days work = 1/120. ( 6women + 3 children) 1 days work = ( 6 * 1/80 + 3 * 1/120) = ( 3 /40 + 1/40 ) = 4/40=1/10. Required time 10 days.
Q 4 - 8 men can finish a piece of work in 40 days . If 2 more men join with them , then the work will be completed in?
Answer : B
Explanation
Let 10 men finish it in x days. More men, less days (Indirect) 10 : 8 :: 40 : x ⇒ 10x = (8 * 40 ) ⇒ x = (8*40) /10 = 32 days.
Q 5 - If a job takes 12 workers 4 hours to complete, how long should it take 15 workers to complete the job?
Answer : C
Explanation
Let the required number of hours b x. More working , less hours (Indirect) 15 : 12 :: 4 : x = > 15 x = ( 12 * 4 ) ⇒ x= (12 * 4 ) /15 = 16 / 5 hrs = 3hrs 12 min.
Q 6 - A contractor undertakes to build a wall in 50 days. He employs 50 people for the same . However, after 25 days , he finds that only 40 % of the work is complete , How many more men need to be employed to complete the work in time?
Answer : B
Explanation
Work done = 40/100 = 2/5 , Remaining work = ( 1 - 2/5 ) = 3/5. 2/5 work is done in 25 days by 50 people. 3/5 work will be done in 25 days by (50 * 5/ 2 * 3/5) people = 75 people. Required number of people = ( 75 ? 50 ) = 25.
Q 7 - 8 men working for 9 hours a day complete a piece of work in 20 days . In how many days can 7 men working for 10 hours a day complete the same piece of work?
Answer : D
Explanation
Let the required number of days be x . Less men , more days ( Indirect) More working hours, less days (Indirect) Men 7: 8 :: 20 : x Working hrs 10 : 9 ∴ ( 7 * 10 * x ) = ( 8 * 9 * 20) ⇒ x = 8 * 9 * 20 / 7 * 10 = 144/7 = 144/7.
Q 8 - If the rent for grazing 40 cows for 20 days in Rs 740, how many cows can graze for 30 days on Rs 222?
Answer : B
Explanation
Let the required number of cows be x. Less rent, less cows (Direct) More days, less cows (Indirect) Rent 740 : 222 :: 40 : x Days 30: 20 ∴ ( 740 * 30 * x) = ( 222 * 20 * 40 ) ⇒ x = 222* 20 * 40 / 740 * 30 = 8 cows.
Q 9 - 2 men and 7 boys can do a piece of work in 14 days ; 3 men and 8 boys can do the same in 11 days . 8 men and 6 boys can do 3 times the amount of this work in
Answer : A
Explanation
Let 1 men 1 days work be 1/x and 1 boy 1 day work be 1/y Then 2/x + 7/y = 1/14 ⇒ 2u + 7v = 1/14 -(i) When u= 1/x, v=1/y. 3/x +8/y =1/11 ⇒ 3u + 8v = 1/11?.(ii) Multiplying (i) by (ii) by 2 and subtracting , we get: 5v = ( 3/14 ? 2/11) = 5/ 154 ⇒ v = 1/154 Putting v = 1/154 in (i) we get : 2u +7* 1/154 = 1/14 ∴ 2u = (1/14- 1/22)= (11-7/54) = 4/154 = 2/77 ⇒ u=1/77. (8 men +6 boys) 1 days work = (8/77 +6/154 ) = 22/154 = 1/7. ∴ 8men and 6 boys can do it in 7 days. They will do thrice of this work in (3*7) days = 21days.
Q 10 - If x men working x hours per day can do x unit of work in x days , then y men working y hours per day would be able to do how much work in y days?
Answer : D
Explanation
More men , more work (Direct) More working hrs , more work (Direct) More days , more work (Direct) Let the required work be z units. Then, Men x:y working hrs x:y :: x:z days x:y ∴ x*x*x*z = y * y* y* x ⇒ z= y3 / x2 units.