Numerical Appli...

Find $$x$$, if $$\dfrac {1}{4!}-\dfrac {1}{x}=\dfrac {1}{5!}$$.

$$A$$ and $$B$$ can complete a task in $$12$$ days. However, $$A$$ had to leave a few days before the task was complete and hence it took $$16$$ days in all to complete task. If $$A$$ alone could complete the work in $$21$$ days, how many days before the work getting over did $$A$$ leave?

A takes $$5$$ days less than $$B$$ to complete the work. Both complete the work in $$6$$ days. In how many days $$A$$ complete the work?

Ram and Shyam together can do a work in $$16$$ days. Shyam takes twice time as Ram takes to do the same work. In how many days Shyam alone can complete that work?

Ram and Shyam together can do a work in $$16$$ days. Shyam takes twice time as Ram takes to do the same work. In how many days Ram alone can complete that work.

$$4$$ men or $$6$$ women can do a work in $$42$$ days. The number of days $$12$$ men and $$3$$ women would take to finish the work is

$$40$$ conservancy workers were employed for $$10$$ days to clean buildings affected by floods. The number of additional workers required to complete the work in $$4$$ days is

$$39$$ persons can repair a road in $$12$$ days, working $$5$$ hours a day. In how many days will $$30$$ persons, working $$6$$ hours a day, complete the work?

The number of ways in which $$9$$ persons can be divided into three equal groups, is

The mean of squares of consecutive odd numbers from 1 to 13 is