Birthday Paradox (Birthday Problem)

You may solve the simple probability, “Given a set of n randomly chosen people, what is the probability of two people having same birthday?” You may also […]

Upstream-Downstream relative speed question

A person rides a cycle at a constant speed. When he drives in the direction of the wind, he is able to go 35 km in 5 […]

Maximum distance with 50 bikes each having fuel capacity of 100 kms

There are 50 bikes, each with a tank that has the capacity to go 100 kms (when the fuel is full). Fuel tanks of all […]

Number of Rectangles on a chess board

Earlier we discussed, how to calculate total number of squares (of all sizes) on the chess board. Here, the problem is, How many rectangles (of […]

Handshakes question

At a party, everyone shook hands with everybody else. There were 66 handshakes. How many people were there at the party?

Speed and time question

Two towns are exactly 100 km apart. Suresh leaves City-A at 3 pm driving at 30 km/hr. After 30 minutes, at 3:30 pm, Ramesh leaves City-B […]

Work & Time question

A man can do a piece of work in 60 hours. If he takes his son with him and both of them work together, then the […]

Time and Speed puzzle

Two friends decided to get together and start riding bikes towards each other, both at a speed of 6 km/hr (starting at the same time). […]

If digits of my age are reversed you will get my son's age…

If the digits of my present age are reversed then I get current age of my son. If one year ago my age was twice […]

Effect on area of rt angled triangle if base is increased and hight reduced

If the base of a Right angled triangle is increased 4 times and height is reduced to half, what will be the effect on its […]