If $\left(\frac{2}{9}\right)^{th}$ part of a tub is filled in 2 minutes, then the remaining part of the tub will be filled in :

A and B can do a work in 9 days and 12 days respectively. If they work on alternate days starting with A, then in how many days will the work be completed?

A can do a certain work in 12 days. B is 60% more efficient than A. How many days does B alone take to do the same work ?

3 men or 15 boys can do a piece of work in 30 days. In how many days will 2 men and 5 boys do this work?

A and B can do a piece of work in 12 days; B and C together can do it in 15 days. If A is twice as good a workman as C, find the number of days in which B alone can do the work?

40 men can complete a work in 48 days. 56 men started for the same work for x days. After x days, 16 men increased, so, the remaining work is completed in $13\frac{1}{3}$ days. Find x?

The ratio of working efficiency of A and B is 4 : 5. If A alone completes the work in 15 days then in how many days can B alone complete the work ?