Question

9. A and B can do a piece of work in 12 days. B and C
together can do it in 15 days. If A is twice as good a
work man as C, find in what time B alone can do it?
A. 12 days
B. 15 days
C. 20 days
D. 24 days aqiqa

Answer 1

A + B = 12 days

B + C = 15 days

Efficiency - A/C = 2/1

Therefore one day work for -

A = 2u and C = 1u

Let the total work be 60u ( LCM of 12 and 15)

One day work for -

A + B = 5u - (1)

B + C = 4u - (2)

Putting the value of A=2u in eq. 1

B = 3u

Now no. of days taken by B to complete the work = 60 / 3 = 20 days

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