Chain Rule - MCQ 2 - Police Constable Exams MCQ

A) 7 1/2
Explanation: After 4 days, there is (10-4) = 6 days food for 50 people. But 10 people left, so there are 40 people left, and let now the same food is for x days for 40 people. So M1*D1 = M2*D2
50*6 = 40*x Solve, x = 15/2

D) 25
Explanation: M1*D1*H1*W2 = M2*D2*H2*W1
50*20*4*(3/4) = (50+x)*40*4*(1/4) Solve x = 25

B) 7
Explanation: Given 1 m = 2 w. So 2 m = 4w 2m+3w 100 pages in 5 hrs, so 4w+3w = 7 women 100 pages in 5 hours. So M1*H1*W2 = M2*D2*H2*W1
7*5*200 = 10*H2*100
Solve H2 = 7

D) 4 hours Explanation: Remaining boys = 3, remaining fruits = 2/5th Eating is work here. So M1*H1*W2 = M2*H2*W1
9*2*(2/5) = 3*H2*(3/5)
Solve, H2 = 4

D) 6
Explanation: Let 100 men complete x work in 10 days after which (100+60) = 160 men complete the remaining (1-x) work in remaining 10 days [Total work to be completed in 20 days] So, M1*D1*W2 = M2*D2*W1 100*10*(1-x) = 160*10*x Solve, x= 5/13 This means that initially employed 100 men can finish 5/13th of work in 10 days, so let they will complete 1 whole work in x days.
M1*D1*W2 = M2*D2*W1
100*10*1 = 100*x*(5/13) Solve, x = 26 This means extra (26-20) = 6 days will be required if additional men are not employed after 10 days.

D) 5
Explanation: 2 m or 5 w 4m + 5w Cross multiply and put in denominator Days = 15*2*5/ [2*5 +5*4]

A) 14
Explanation: After 1 day, x men were to work for 8 days, but 6 men left, now (x-6) men will complete the same remaining work in (8+6) = 14days.
So x*8 = (x-6)*14 Solve, x = 14

B) 2.5 minutes Explanation: 1/5 * 10 = (4/5) * x x = 5/2

C) 54
Explanation: 30*40*6*(3/5) = 20*D2*8*(2/5)
D2 = 54

B) 3.5 days Explanation: After 2 days, let x food was left, which means that 10 people ate x food for 3 days, so let us find the number of days for which x food has lasted for 20 people.
Eating burgers will be considered as a work. So M1*D1*W2 = M2*D2*W1
10*3*x = 20*D2*x Solve D2 = 3/2 So 20 people first ate the food for 2 days, after it the remaining food they would have eaten in 3/2 days more so total (2 + 3/2) days

C) 4
Explanation: M1*H1*D1 = M2*H2*D2
4*5*16 = 20*4*D2
Solve D2 = 4

D) 2/5
Explanation: M1*D1*H1*W2 = M2*D2*H2*W1
20*6*4*W2 = 30*2*8*(2/5)
Solve W2 = 2/5

B) 10
Explanation: Total work to be completed in 14 days, so (additional men+10 men already employed) will have to complete remaining work (1 – 2/5 ) = 3/5 of work in (14-8) = 6 days.. let x is additional men M1*D1*H1*W2 = M2*D2*H2*W1
10*8*5*(3/5) = (10+x)*6*5*(2/5) Solve x = 10

D) 9 hours Explanation: Answer sheets are work here. So M1*D1*H1*W2 = M2*D2*H2*W1
9*12*5*2 = 4*30*H2*1
Solve, H2 = 9

A) 42
Explanation: After 10 days, there is (45-10) = 35 days food for 150 men. But 25 men left, so there are 125 men left, and let now the same food is for x days for 125 men. So M1*D1 = M2*D2
150*35 = 125*x Solve, x = 42

D) 5
Explanation: Let 200 men complete x work in 40 days after which (200+100) = 300 men complete the remaining (1-x) work in remaining 10 days [Total work to be completed in 50 days] So, M1*D1*W2 = M2*D2*W1 200*40*(1-x) = 300*10*x Solve, x= 8/11 This means that initially employed 200 men can finish 8/11th of work in 40 days, so let they will complete 1 whole work in x days.
M1*D1*W2 = M2*D2*W1
200*40*1 = 200*x*(8/11) Solve, x = 55 This means extra (55-50) = 5 days will be required if additional men are not employed after 40 days.

D) 45
Explanation: 4 w = 2m, so 1w = 1/2 m And then 20 w = 10 m, so we have to find the number of days for 10 men to complete remaining work (1 – 2/5) = 3/5th .
M1*D1*H1*W2 = M2*D2*H2*W1
20*10*6*(3/5) = 10*D2*4*(2/5)
Solve, D2 = 45 days

A) 150
Explanation: Binding books is a work, so W2*S1*H1 = W1*S2*H2
W2*50*4 = 100*150*2
Solve W2 = 150 books

B) 14 days Explanation: 2 m = 3 b So 1m = 3/2 b 6m + 8b = 6 * (3/2) b + 9b = 18 b So we have to find the number of days for 18 boys 3 boys do 1 work in 14 days working 6 hours, let 18 boys do twice work in x days working 2 hrs each day, then B1*D1*H1*W2 = B2*D2*H2*W1
3*14*6*2 = 18*x*2*1 Solve x = 14 days

B) 8 hours Explanation: Eating burgers will be considered as a work. So M1*H1*W2 = M2*H2*W1
20*2*200 = 10*H2*100
Solve H2 = 8