Question

P can do a piece of work in 15 days . P and R can do it in 10 days and P, Q and R in 6 days . In how much days can P and Q together do it ?

Answer 1

Answer:

P and Q would take 11 days

Answer 2

Answer:

7.5 days

Step-by-step explanation:

given

p=15 days

p+R=10

p+q+r=6

solved

p=1/15

p+R=1/10

p=1/15

1/15+R=1/10

R=1/10-1/15

R=1/30

hence,P+Q+R=1/6

1/15+1/30+q=1/6

Q=1/15

we have to find

p+Q= 1/15+1/15

2/15

days=15/2= 7.5 days