Name a key which is hardest to turn.

The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member. Find how much younger is the new member ?

A red house is made out of red bricks. A yellow house is made out of yellow bricks. And, a blue house is made out of blue bricks. So, what is a greenhouse made of?

There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes

Find the next number in the sequence

5 12 24 36 ?

Usually, a boxing match consists of twelve rounds. In a particular friendly match between two heavyweights, the match was finished in the ninth round itself as one of the boxers knocked out the other one.

But, in that fight, no man threw even a single punch.

How can this be possible?

John bought a new car. He has a habit of eating ice cream from a particular ice cream shop while returning home from office. Whenever, he eats strawberry ice cream, he faces no problem. But whenever, he eats chocolate ice cream, the car starts giving problem. At first, he thinks, it is just a co-incidence but when this awkward incident happens for 3-4 times, he reports this problem to the company.

The mechanic of the company checks but finds no problem at all. The next day, when he stops by to eat chocolate ice cream, the car again starts giving problem.

Can you find the possible reason?

The doctor advised his patient to take a tablet after every fifteen minutes. He gave him five tablets in total.

How much time will he take to have all the five tablets?

How do you go from 98 to 720 using just one letter?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.