Question

A can do a piece of work in 4 hours, B and C can do it in 3hrs, A and C can do it in 2hrs. How long will B alone take to do it?

Answer 1

Follow The Steps Bud! :)

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Let a,b & c be the number of days taken by A, B & C to complete the work alone.

Given, A can do a piece of work in four hours.

=> 1/a = 1/4——————(1)

B and C together can do it in 3 hours,

=> 1/b + 1/c = 1/3———-(2)

A and C together can do it in 2 hours,

=> 1/a + 1/c = 1/2———-(3)

Using (1) & (3)

1/c = 1/2 - 1/4 = 1/4——-(4)

Using (2) & (4)

1/b = 1/3 - 1/4 = 1/12

=> b = 12

=> The number of days taken by B to complete the work alone is 12 hours.

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