#### 42&43

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**Question**

18-10-07

**Answer**

Q No 43 . A and B completed a work in 8 days .had a worked twice the speed and B at one third of the speed it would have taken them 6 days to complete the job .how much time it take for B alone

A+B=1/8 -----I

2A+(1/3)B =1/6 -----II (A’s efficiency will be double and B efficiency will be one third )

SOLVE I AND II

B=1/20

TOTAL NUMBER OF DAYS WILL BE 20 DAYS

Q 42. A takes 5 days more than B to do a certain job and 9 days more than C; A and B together can do the job in same time as C. How many days A would take to do it?

First method

Let days taken by A =x

B days will be =x-5 , one day work =1/x-5

C days will be =x -9, one day work =1/x-9

A+B=C (given)

1/x+1/x-5=1/x-9

After solving we get x=15

Other method

Put values form option and satisfy the equation

If we put x=15 then it will satisfy above equation

1/15+1/10 =1/6

1/6=1/6