Numerical Appli...

If $15$ men can complete a piece of work in $30$ days, then how many days will it take for $18$ men to complete it?

A tea party is arranged for $16$ people along two sides of a large table with $8$ chairs on each side. Four men to sit on one particular side and two on the other side. In how many ways can they be seated?

In order to complete a work in $28$ days, $60$ men are required. How many men will be required if the same work is to be completed in $40$ days?

$50$ labourers can dig a pond in $16$ days. How many labourers will be required to dig another pond in $20$ days, which is double in size? 

Seven girls are to dance in a circle. In how many different ways can they stand on the circumference of the circle?

If it was Saturday on 17th December, 2002 then what was the day on 22nd December, 2004?

If $3$ men or $6$ boys can finish a work in $20$ days , then how long will $4$ men and $12$ boys take to finish the same work ?

The heights (in $cm$) of $8$ girls of a class are $140, 142, 135, 133, 137, 150, 148$ and $138$ respectively. Find the mean height of these girls.

Six taps can fill an empty cistern in $8$ hours. How much more time will be taken, if two taps go out of order? Assume all the taps supply water at the same rate.

If $12$ men or $18$ women can complete a piece of work in $7$ days , then in how many days can $4$ men and $8$ women complete the same work ?