How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

Three brothers Jacob, John, and James live in Mexico City. The product of the ages of these brothers is 175. Jacob and John are twins. How old is James?

It is a six-letter word.
The first four letters are me.
The second and last letters are the same.
The fourth second and last letter is payment.

Who is it?

Spot the cat in the picture below

Can you find a seven digit number which describes itself. The first digit is the number of zeros in the number. The second digit is the number of ones in the number, etc. For example, in the number 21200, there are 2 zeros, 1 one, 2 twos, 0 threes and 0 fours.

What brings you down but never up?

Different lights make me strange by changing me into different sizes. What am I?

Divide 110 into two parts so that one will be 150 per cent of the other. What are the 2 numbers?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?