Question

P,Q and R together can build a house in 8 days. P and Q can build the house seperately in 20 days and 24 days resp. In how many days can R build the house alone?

Answer 1

Answer:

30 days

Step-by-step explanation:

P - 20 days

Q - 24 days

R -- x days

P + Q + R = 8

1/20 + 1/24 + 1/x = 1/8

11/120 + 1/x = 1/8

1/x = 1/8 - 11/120

1/x = (15-11)/120

1/x = 1/30

so

x = 30 days,

R can complete the building in 30 days