Time and Work

If $ A$ and$ B$ together can complete a piece of work in $15$ days and $ B$ alone in $ 20$ days. In how many days a alone can complete the work ?

If $6$ men and $8$ boys can do a piece of work in $10$ days and $26$ men and $48$ boys can do same in $ 2 $ days, the time taken by $15$ men and $20$ boys to do the same type of work will be :

A , B and C together can complete a piece of work in $10$ days. All the three started working at it together and after $4$ days A left. Then B and C together completed the work in $10$ more days. A alone could complete the work in :

$36$ workmen are employed to finish a certain work in $48$ days but it is found that in $24$ days , only $\dfrac{2}{5}$ work is done. How many more men must be taken to finish the work in time?

$2$ men and $5$ women can do $\dfrac{1}{4}$th of a job in $3 $days . After $3$ days , $1 $ man joined team and they completed another$\dfrac{ 1}{4}$ th of the job in $ 2$ days . How many men can complete the job in $4$ days ?

If $34$ men completed $\dfrac{2}{5}$th of a work in $8$ days working $9$ hours a day. How many more man should be engaged to finish the rest of the work in $6$ days working $9$ hours a day?

A and B together can complete a work in $4$ days. A alone can finish the work in $12$ days, In how many days B alone can finish the work?

$6$ typist working $5$ hours a day can type the manuscript of a book in $16$ days. How many days will $4$ typists take to do the same job, each working $6$ hrs a day?

Twelve identical machines, running continuously at the same constant rate, take $8$ days to complete a shipment. How many additional machines, each running at the same constant rate, would be needed to reduce the time required to complete a shipment by $2$ days?

A group of workers can do a piece of work in $24$ days. However as $7$ of them were absent it took $30$ days to complete work. How many people actually worked on the job to complete it?

$15$ persons complete a work in $4$ days by working $6$ hours a day. How many days it will take to complete the work if $5$ persons work same hours per day?

A man can make $18$ cakes in $6$ days by working $6$ hours a day. How many cakes can he make in $24$ days if he works $6$ hours a day?

If A is three times as efficient as B & A can complete a work in $40$ days less time than B. Find in how many days both can complete the work

The amount of time taken to paint a wall is inversely proportional to the number of painters working on the job. If it takes 3 painters 5 days to complete such a job, how many days longer will it take if there are only 2 painters working?