Numerical Appli...

A water tank is $$\displaystyle\frac{2}{5}$$th full. Pipe $$A$$ can fill the tank in 10 minutes and pipe $$B$$ can empty it in $$6$$ minutes. If both the pipes are open, how long will it take to empty or fill the tank completely?

$$A$$ can do a work in $$15$$ days and $$B$$ in $$20$$ days. If they work on it together for $$4$$ days, then the fraction of the work that is left is:

Two workers A and B working together completed a job in $$ 5$$ days. If A worked twice as efficiently as he actually did and B worked $$\displaystyle \frac{1}{3}$$ as efficiently as he actually did the work would have been completed in  $$3$$ days. A alone could complete the work in

$$A$$ alone can do a piece of work in $$6$$ days and $$B$$ alone in $$8$$ days. $$A$$ and $$B$$  undertook to do it for $$Rs. 3200.$$ With the help of $$C,$$ they completed the work in $$3$$ days. How much is to be paid to $$C$$?

Ravi and Kumar are working on an assignment. Ravi takes $$6$$ hours to type $$32$$ pages on a computer, while Kumar takes $$5$$ hours to type $$40$$ pages. How much time will they take, working together on two different computers to type an assignment of $$110$$ pages?

$$A$$ and $$B$$ together can do a piece of work in $$30$$ days. $$A$$ having worked for $$16$$ days, $$B$$ finishes the remaining work alone in $$44$$ days. In how many days shall $$B$$ finish the whole work alone?

A man a woman and a boy can complete a job in $$3, 4$$ and $$12$$ days respectively. How many boys must assist 1 man and 1 woman to complete the job in $$\displaystyle \frac{1}{4}$$ of a day?

$$24$$ men can complete a work in $$16$$ days, $$32$$ women can complete the same work in $$24$$ days. $$16$$ men and $$16$$ women started working and worked for $$12$$ days. How many more men are to be added to complete the remaining work in $$2$$ days?

$$12$$ men can complete a piece of work in $$4$$ days while $$15$$ women can complete the same work in $$4$$ days $$6$$ men start working on the job and after working for $$2$$ days all of them stopped working. How many women should be put on the job to complete the remaining work if it is to be completed in $$3$$ days ?

$$A$$ and $$B$$ together can do a piece of work in $$12$$ days which $$B$$ and $$C$$ together can do in $$16$$ days. After $$A$$ has been working at it for $$5$$ days and $$B$$ for $$7$$ days, $$C$$ finishes it in $$13$$ days. In how many days $$C$$ alone will do the work ?