Question

A and B together can do a piece of work in 12 days, B and C together in 15 days. If A is twice as good a work man as C, then in how many days will B alone do it?
(a) 10 days (b) 15 days (c) 20 days (d) 25 days
Answer this with explaination... correct answer and no spams.. explaination is must... thank you in advance​

Answer 1

20 days

Step-by-step explanation:

Given,

A = 2C

Assume Total work = 60 unit (LCM OF 12,15)

A+B can do 60 unit in 12 days

or 2C + B can do 60unit in 12 days

2C + B can do 60/12= 5 unit in 1 day

B+C can do 60 unit in 15days

B+C can do 60/15=4 unit in 1 day.

Therefore,

B + 2C = 5

- B + C = 4

C = 1

If C does 1unit in 1 day then B does 3 units in 1 day.

B alone can do the work in 60/3 = 20 days.