Question : Pipes A and B together can fill a tank in 10 hours. Pipes B and C together can fill the same tank in 12 hours. Pipes A and C together can fill the same tank in 15 hours. In how many hours can pipe B alone fill the same tank?

Option 1: $\frac{120}{7}$ hours

Option 2: $15$ hours

Option 3: $\frac{120}{11}$ hours

Option 4: $\frac{155}{13}$ hours

Question : A and B together can finish a work in 7.2 hours. If B alone can finish the same work in 18 hours, then A alone can do it in:

Option 1: 18 hours

Option 2: 12 hours

Option 3: 10 hours

Option 4: 15 hours

Question : P, Q, and R alone can complete a piece of work in 30 hours, 10 hours and 15 hours respectively. In how much time will they finish the work if they work together?

Option 1: 5 hours

Option 2: 4 hours

Option 3: 8 hours

Option 4: 10 hours

Question : A alone can do $\frac{1}{10}$th part of a work in 8 hours. B alone can do $\frac{1}{5}$th part of the same work in 4 hours. If they work together, then how many hours will they take to complete $\frac{9}{16}$th part of the same work?

Option 1: 9 hours

Option 2: 5 hours

Option 3: 8 hours

Option 4: 4 hours

Question : A, B, and C together can do a piece of work in 6 days. A and B together can do the same work in 12 days. B alone can do the same work in 18 days. In how many days can A and C together do the same work?

Option 1: 9 days

Option 2: 10.5 days

Option 3: 8 days

Option 4: 7.5 days