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.

Questions and Answers

Q 1 - A garrison of 500 men had provisions for 24 days . However a reinforcement of 300 men arrived . The food will now last for

A - 18 days

B - 35/2 days

C - 16 days

D - 15 days

Answer : D

Explanation

Let the required number of days be x.
More men , less days      (indirect)
800 : 500  :: 24 : x ⇒ 800x = (500 * 24 ) ⇒ x = (500 * 24 ) / 800  = 15.
∴ The food will now last for 15 days.

Q 2 - 10 men can finish the construction of a wall in 8 days. How many men are added to finish the work in half a day?

A - 160

B - 100

C - 120

D - 150

Answer : D

Explanation

Let the total number of men be x.
Less days , more men required    (Indirect)
1/2 : 8 :: 10 : x ⇒ 1/2 x =(8* 10 )⇒ x= (8* 10* 2*) = 160.
Number of men to be added = (160- 10 )=150.

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?

A - 9 days

B - 12 days

C - 10 days

D - 8 days

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 - A man and a boy working together can complete a work in 24 days . If for the last 6 days man alone the work , then it is completed in 26 days. How long will the boy take to complete the work alone?

A - 72 days

B - 20 days

C - 24 days

D - 36 days

Answer : A

Explanation

Let 1 men 1 days work be 1/x and 1 boy 1 days work be 1/y Then,
1/x + 1/y = 1/24
20/x + 20 / y +  6 /x )1 ⇒ 20 (1/x + 1/y) + 6/x = 1 ⇒ (20 * 24) + 6/x = 1 
⇒ 6/x = (1- 20/24) = 4 / 24 = 1/6 ⇒ 1/x = 1/ 36 ⇒ 1/y = ( 1/24 - 1/ 36 ) = 1/72.
∴ The boy along will do it in 72 days.

Q 5 - 40 men take 8 days to ears Rs 2000. How many men will earn Rs 200 in 2 days?

A - 1

B - 2

C - 3

D - 4

Answer : A

Explanation

Let  the required number of  men  b  x.
Less  earning , less men     (Direct)
Less days , less men      (Direct)
Earning     2000  : 200
:: 40 : x
Days       8 :  2
∴ (2000 * 8 * x ) = (200 * 2 * 40 ) ⇒ x = 200* 2 * 40 / 2000 * 8  = 1 .
Required number of men = 1.

Q 6 - A garrison of 500 men had provisions for 27 days. After 3 days ,a reinforcement of 300 men arrived. The remaining food will now last for how many days

A - 15

B - 16

C - 17

D - 18

Answer : A

Explanation

500 men had provisions for (27-3) = 24 days . Let the food for 800 men last for x days.
More men , less days         (Indirect)
800: 500 :: 24 : x ⇒ 800x = (500 * 24 ) ⇒ x = (500 * 24)/800 = 15 days.

Q 7 - Running at the same constant rate , 6 identical machines can produce 2700 bottle per minute . At this rate , how many bottles could 10 such machines produce in 4 minutes?

A - 648

B - 1800

C - 2700

D - 10800

Answer : B

Explanation

Let the required number  of bottles be x .
More machines, more bottles    ( Direct)
More time, more bottles      ( Direct)
Machines         6 : 10
:: 2700 : x
Time     1:4
(6 * 1 * x) = 10 * 4 * 2700 ) ⇒ 10 * 4 * 2700 / 6 = 1800 bottles.

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?

A - 6

B - 8

C - 5

D - 12

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 - If a certain number of workmen can be a piece of work in 25 days , in what time will another set of an equal number of men do a piece of work twice as great , supposing that 2 of the first set can do as much work in an hour as 3 of the second set can do in an hour

A - 60 days

B - 75 days

C - 90 days

D - 105 days

Answer : B

Explanation

Let the required time be x days  .
Ratio of their speed = 1/2 : 1/3.
More work , more time    (Direct)
Less speed, more work    (Indirect)
Work 1:2                      :: 25:x
Speed 1/3 : 1/2 
∴ (1* 1/3 *x) = 2 *1/2 *25 ⇒ x=75days.

Q 10 - A contractor employed 30 men to do a piece of work in 38 days. After 25 days he employed 5 men more and the work was finished one day earlier. How many days , he would have been behind , if he had not employed additional men?

A - 1 day

B - 5/4 days

C - 3 days

D - 7/4 days

Answer : A

Explanation

After 25 days , 35 men finish the remaining work in (38 - 25 - 1) = 12 days.
35 men can finish the remaining work in 12 days.
30 men can finish it in (12 * 35) /30  days = 14 days , i.e. 1 day behind.
aptitude_chain_rules.htm
Advertisements