Question

A can do a certain work in 4 hours. A and B together do the same work in 2 hours. B and C
together do it m 3 hours. How long will C alone take to do it?​

Answer 1

Answer:

C can do the work in alone in 12 hrs (hope i am correct)

Step-by-step explanation:

Let the time taken by B to do the work alone be x hrs and C to do the work alone be y hrs

Time taken by A to complete the work alone = 4hrs (Given)

Part of work done by A in 1 hr = 1/4

Part of work done by B in 1 hr = 1/x

Part of work done by C in 1 hr = 1/y

Part of  work done by A in 2 hrs = 2/4 = 1/2

Part of work done by B in 2 hrs = 2/x

Part of work done by B in 3 hrs = 3/x

Part of work done by C in 3 hrs = 3/y

According to question,

A and B can do the work in 2 hrs

=> 1/2 + 2/x = 1 (since 1 work is done in 2 hrs)

=> 2/x = 1/2

=> x = 4hr   ------------------------------------(1)

Also,

B and C can do the work in 3 hrs

=> 3(1/x + 1/y) = 1

=> 3/4 + 3/y = 1 [From (1)]

=> 3/y = 1-3/4

=> 3/y = 1/4

=> y = 12 hrs

Therefore, C can do the work alone in 12 hrs.

HOPE IT HELPS