Time and Work Easy Questions and Answers | Page - 89

Time and Work

A can do a piece of work in 70 days and B is 40% more efficient than A. The number of days taken by B to do the same work is

1. 40 days
1. 60 days
1. 50 days
1. 45 days

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A : B = D₂ : D₂
⇒ 100 : 140 = D₂ : 70
⇒ 100 × 70 = 140 × D₂
⇒ D₂ = 100 × 70 = 50 days.
140

Aliter : Using Rule 17,
Here, x = 70, r = 40%
Time taken by B
= x × 100
100 + R

= 70 × 100 = 50 days
100 + 40

Correct Option: C

A : B = D₂ : D₂
⇒ 100 : 140 = D₂ : 70
⇒ 100 × 70 = 140 × D₂
⇒ D₂ = 100 × 70 = 50 days.
140

Aliter : Using Rule 17,
Here, x = 70, r = 40%
Time taken by B
= x × 100
100 + R

= 70 × 100 = 50 days
100 + 40