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 - 3 men or 5 women can finish a piece of work in 12 days. How long will 6 men and 5 women take to finish the work?

A - 4 days

B - 10 days

C - 15 days

D - 20 days

Answer : A

Explanation

3 men = 5 women ⇒ 6 men =10 women
⇒ (6 men +5 women )= 15 women.
Let the required number  of days be x.
More women , less days      (Indirect)
15 : 5 :: 12 :  x ⇒ 15x = (5* 12 ) ⇒ x= (5*12)/15 = 4 days

Q 3 - 20 men complete one ? third of a piece of work in 20 days . How many more men should be employed to finish the rest of the work in 25 more days?

A - 10

B - 12

C - 15

D - 20

Answer : B

Explanation

Work done =1/3  , Remaining work = (1 - 1/3 ) = 2/3
Let number of more men to be employed be x.
More work, More men       (Direct)
More days , less men     (Indirect)
Work 1/3 : 2/3
:: 20 : (20 +x)
Days 25 : 20
1/3 * 25 * ( 20+ x) = 2/3 * 20 *20 ⇒ (20 + x) = 800/25 = 32 ⇒ x = (32-20) = 12.

Q 4 - 8 men and 12 children can do a piece of work in 9 days . A child takes double the time to do a work than the men. In how many days 12 men can complete the work?

A - 21/2 days

B - 14 days

C - 18 days

D - 27/2 days

Answer : A

Explanation

2 children = 1 men ⇒ (8 men + 12 children ) = 14 men.
Let the required number of days be x. 
Less men , more day       (Indirect )
12 : 14:: 9 : x ⇒ 12x = ( 14 * 90 ⇒ ( 14* 9 ) /12 = 21 /2 = 21/2 days.

Q 5 - Two persons can complete a piece of work in 9 days. How many more persons are needed to complete double the work in 12 days?

A - 1

B - 2

C - 3

D - 4

Answer : A

Explanation

Let the required number of persons be x .
More work, more  persons          (direct)
More  days  , less persons          (Indirect)
Work      1:2
:: 2 : (2+x)
Days    12:9 
 1*12 * ( 2 + x ) = (2 * 9 *2 ) ⇒ ( 2 + x ) = 36/12 = 3 ⇒ x=1.

Q 6 - A garrison of 3300 men had provisions for 32 days , when given at the rate of 850 gm per head . At the end of 7 days , a reinforcement arrived and it was found that the provisions would last 17 days more , when given at the rate of 825 gm per head . What was the strength of the reinforcement?

A - 1500

B - 1600

C - 1700

D - 1800

Answer : C

Explanation

Let the required strength of reinforcement be x.
3300 men had provisions for (32-7 ) = 25 days.
Less food per head , more persons    (Indirect)
Less days , more persons         (Indirect)
Food per days  825 : 850
:: 3300 : (3300  x )
Days          17 : 25
∴ 825 * 17 * (3300 + x ) = 850 * 25 * 3300
⇒ ( 3300 + x ) = 850 * 25 * 3300/825 * 17 = 5000 ⇒ x = ( 5000 - 3300) = 1700 men.

Q 7 - If 6 persons working 8 hours a day earn Rs 16800 per week , then 9 persons working 6 hours a day will earn per week?

A - Rs 17800

B - Rs 18900

C - Rs 19200

D - Rs 26800

Answer : B

Explanation

Let the required earning  be Rs x.
More persons , more earning      ( Direct)
Less hrs per day, less earning      ( Direct)
Persons   6:9
:: 16800 : x
Hrs / day      8 : 6
(6 * 8 *x ) = ( 9 * 6 * 16800) = X =9 * 6 * 16800/ 6 *8  = 18900.

Q 8 - In a hospital, there is a consumption of 1350 litres of milk for 70 patients for 30 days. How many patients will consume 1710 litres of milk in 28 days?

A - 59

B - 85

C - 95

D - 105

Answer : C

Explanation

Let the required number of patients be x .
More milk, more patients        (Direct)
Less days , more patients        (Indirect)
Litres   1350:1710
::70 : x 
Days       28 : 30
∴ ( 1350 * 28 * x ) = ( 1710 * 30 * 70) ⇒ x= 1710 * 30 * 70/ ( 1350 * 28 ) = 95 patients.

Q 9 - If 5 engines consume 6 metric tonnes of coal when each is running 9 hour per day, how much coal will be needed for 8 engines , each running 10 hours a days , it being give that 3 engines of former type consume as much as 4 engines of latter type?

A - 8 metric tonnes

B - 80/3 metric tonnes

C - 25/8 metric tonnes

D - 150/25 metric tones

Answer : A

Explanation

Let the quantity of coal required be x metric tonnes.
More engine, more coal     (Direct)
More hrs/days, more coal       (Direct)
More rate of consumption, more coal     (Direct)
Engine           5:8
Hrs/days        9:10                                      :: 6 : x
Rate of consumption      1/3 : 1/4
∴ (5*9*1/3*x) = (8*10 *1/4 *6)⇒ x= 120/15 = 8 metric tonnes.

Q 10 - 20 men complete one third of a piece of work in 20 days. How many more men should be employed to finish the rest of the work in 25 more days?

A - 10

B - 12

C - 15

D - 20

Answer : B

Explanation

Work done = 1/3, Remaining work = (1- 1/3 ) = 2/3
Let the number of additional men be x.
More work, more men      (Direct)
More days , less men         (Indirect)
Work 1/3 : 2 /3
:: 20 : (20 +x)
Days 25:20
   1/3 * 25 * ( 20 + x) = 2 /3 * 20 *20 ⇒ (20 +x) = 32 ⇒ x=12.
Required number of days  = 12.

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