Basic Math MCQ 14 (Work capability comparison)

MCQ 14:  A and B can finish a work 30 days if they work together. They worked together for 20 days and then B left. A finished the remaining work in another 20 days. In how many days A alone can finish the work?

a)  70               b) 50                       c) 40                  d) 60

Solution:

Let the Work be W

A and B take 30 days to complete the work

i-e

30 days (A+B) = W

1day (A+B)= W/30

20 days (A+B) = 20W/30

Remaining work ;

\[ =W-\frac{20W}{30}=\frac{10W}{30}=\frac{W}{3} \]

A finished this remaining work in 20 days i-e

20 days  for A = ​\( \frac{W}{3} \)​

or

​\( \frac{W}{3} \)​ =20 days for A

W = 60 days for A

So A can finish the work W alone in 60 days !

So option d is correct

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