Question

If 30 workers can do a work in 20 days. After working for "X" days 10 workers leave the job and the task is completed in 25 days?
Choose one of the following answers
5
10
15
20​

Answer 1

Answer:

x = 10,  2nd option

Step-by-step explanation:

30 workers can do a work in 20 days

1 worker's one day work =1/600

So in x days work done=x/20

Work left=1-x/20=(20-x) /20

Now the remaining work was completed by 20 workers in 25-x days

So 20(25-x)/600=(20-x)/20

(25-x)/30=(20-x)/20

2(25-x)=3(20-x)

50-2x=60-3x

3x-2x=60-50

x=10 days