Question

Ntse MAT question A is 3 times more efficient than B. Hence, he takes 60 days less in painting a room. In how many days, work will be completed, if A and B both work together? (1) 30 days (2) 45 days (3) 22 1 2 days (4) 17 1 2 days

Answer 1

The answer is (3)
Efficiency  A : B
n = 3n
3n - n = 60
n = 30
A = 30, B = 90
(A + B) = (30*90)/120=22 1/2 Days

Answer 2

Answer:

$22 \frac{1}{2} days$

Step-by-step explanation:

We are given that A is 3 times more efficient than B

Let A completes work in x days

So, B completes work in 3x days

A takes 60 less days than B

So, 3x-x = 60

2x=60

x=30 days

So, A complete work in 30 days

A 's 1 day work = $\frac{1}{30}$

B complete work in 90 days

B's 1 day work = $\frac{1}{90}$

So, they do work together in 1 day =$\frac{1}{30} + \frac{1}{90} = \frac{4}{90}$

So, they complete work together =$\frac{90}{4}=22\frac{1}{2} days$

Hence A and B both work together in $22 \frac{1}{2} days$