Find the next number in the series below

21 32 54 87 131 ?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

You have two rectangular wires.

Both of them have property that when you light the fire from one end , it will take 60 minutes to get completely burn.

However, they do not burn at consistent speed (i.e it might be possible 1st 20% burn in 50 minutes and 80% can burn in 10 minutes).

So how could you measure 45 minutes ?

Two batsman each on 94 runs. Seven runs needed to win in last 3 balls. Both make 100*. How?

What four weights can be used to balance from 1 to 30 pounds?

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?

Two-person want to cross a river. Only one boat is present on the riverside that can carry only one person at a time.

However, they still manage to cross the river. How is it possible?

I add 5 to 9 and get 2. The answer is correct, so what am I?

A sundial has the fewest moving parts of any timepiece. Which has the most?

The person who makes it has no need for it; the person who buys it has no use for it. The person who uses it can neither see nor feel it. What is it?