Question

9. A and B together can finish a piece
of work in 10*2/7 days. B and C
together can finish the same
piece of work in 13*1/3 days B
is 25% more efficient than C.
In how many days A and C
together can finish the same
piece of work ?
​

Answer 1

A+B - 72/7

B+C -40/3

taking Lcm we get total work =360

and A+B one days work = 35

and B+C one days work = 27

now B Is 25 % more efficient than c

hence B :C =125:100 =5:4

now 9 units =27

or, 5 units =15 = B one days work

and 4 units =12 = C one days work

therefore A one days work = 35-15 =20

now A +C one day work = 20 +12 =32

total.work =360

hence no. days taken =360 /32 =90/8=45/4