Five years ago Fifi was five times older than his son. After five years, Fifi will be 5 years more than two times the age of his son. Find the present age of Fifi and his son.

Two poles of heights ^@ 7 \space metres^@ and ^@47 \space metres^@ stand vertically on a plane ground. If the distance between their feet is ^@42 \space metres^@, find the distance between their tops.

If ^@A(18,7)^@, ^@B(14,17)^@, and ^@C(8,5)^@ are the vertices of ^@\Delta ABC^@ and ^@AD^@ is its median. Then the area of ^@\Delta ABD ^@ and ^@\Delta ADC ^@ is:

A rope is tightly stretched and attached from top of a vertical tower to the ground. The angle made by rope with ground is 30°. If length of the rope is m, find height of the tower.

A can is in the shape of a frustum of a cone of height ^@43 \space cm^@. The diameters of its two circular ends are ^@15 \space cm^@ and ^@12 \space cm^@. Find the capacity of the can.(Use ^@ \pi = \dfrac { 22 } { 7 } ^@)

There are 4 books belonging to 4 students. The books were put into a box, and each student pulls out an book one after the other. What is the probability that each student gets his or her own book?