Question

A,B,C can complete a work in 15,20 and 30 respectively.They all work together for two days then A leave the work,B and C work some days and B leaves 2 days before completion of that work.how many days required to complete the whole work?
A)

Answer 1

AnSwer:-

• Total number of days taken to complete the work = 11 3/5 days.

GiVen:-

• Given A,B,C can complete a work in 15,20 and 30 respectively.

To Find:-

• Total number of days required to complete the whole work.

Explanation:-

Here,

The total work is given by the LCM of 15, 20, 30 i.e, 60.

1 day work of A= 60/15 = 4 units

1 day work of B= 60/20 = 3 units

1 day work of C= 60/30 = 2 units

(A + B + C) worked for 2 days = (4 + 3 + 2) 2 = 18 units

Let B + C worked for x days = (3 + 2) x = 5x units

C worked for 2 days = 2 x 2 = 4 units

Then, 18 + 5x + 4 = 60

$\sf \longmapsto \: 22 + 5x = 60 \\ \sf \longmapsto 5x = 38 \\ \sf \longmapsto \: x = 7.6$

Therefore, total number of days taken to complete the work = 2 + 7.6 + 2 = 11.6 = 11 3/5 days.