Numerical Appli...

The length of the base of a square pyramid is $2\ cm$ and the height is $6\ cm$. Calculate the volume.

If $3$ men with $4$ boys can earn $Rs. 210$ in $7$ days and $11$ men with $13$ boys can earn $Rs. 830$ in $8$ days, in what time will $7$ men with $9$ boys earn $Rs. 1100$?

16 men can do a piece of work in 16 days. 4 days after they started the work 8 more men joined them. How many days will they now take to complete the remaining work?

A contractor employed 210 men to build a house in 60 days. After 12 days, he was joined by 70 more men. In how many days will the remaining work be finished?

Choose the correct answer from the alternatives given :
Two taps can separately fill a cistern in $20$ and $30$ minutes respectively. Each of the taps is opened for a minute in turn, but due to a hole at the bottom of the cistern and discharge of the water through that, it takes $3$ minutes more to fill the cistern. If the cistern is full of water, find the time taken by the hole to empty it.

Choose the correct answer from the alternatives given.
A contractor took a contract for building $12$ kilometre road in $15$ days and employed $100$ labours on the work. After $9$ days he found that only $5$ kilometre road had been constructed. How many more labours should be employed to ensure that the work may be completed with in the given time?

A telephone number $d_1d_2d_3d_4d_5d_6d_7$ is called memorable if the prefix sequence $d_1d_2d_3$ is exactly the same as either of the sequence $d_4d_5d_6$ or $d_5d_6d_7$(or possibly both). If each $d_1\epsilon\{x|0\leq x\leq 9, x\epsilon W\}$, then number of distinct memorable telephone number is(are).

An alphabet contains a $A^{'s}$ and b $B^{'s}$ . (In all a+b letters ). The number of words each containing all the $A^{'s}$ and any number of $B^{'s}$, is 

The maximum number of intersection points of n circles and n straight lines , among themselves  is 80.The value of n is

The number of ways in which $6$ rings can be worn on the four fingers of one hand is