Find the next number in the series below

21 32 54 87 131 ?

During which month do people sleep the least?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

Can you find out which triangle will have a bigger area among the following?
1. A triangle with sides 300, 400 and 500
2. A triangle with sides 300, 400 and 700

Ten coins have been arranged as you can see in the given picture. In this arrangement, a triangle is formed pointing upwards. You have to invert the position of the triangle and make it point downwards while changing the position of 3 coins only. Can you do it?

Women do it once a year after they turn 19 but men get to do it only once in a lifetime. What is it?

Move three sticks of the spiral below to form a square.

A man was going to bleach his socks because they had gotten muddy the day before. As he was pouring the bleach into the washing machine, he spilt some on the floor. He got some cleaning fluid and mopped it up with a rag. Minutes later he was dead. What killed him?

What is so fragile that saying its name breaks it?