If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

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

He does not have any heart but still, He manages to live.
If you kill him, you will eventually die but yet you kill him.
He cannot run, who is He?

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?

Without looking at a calendar, within a minute name, a boy's name using 5 consecutive 1st letters of 5 consecutive months

In the following series, a set of numbers is progressing with a particular pattern. Can you deduce that pattern and find the missing set?

(2 + 6), (21 + 6), (58 + 6), (119 + 6), ___

Our product and our sum always give the same answer. Who are we?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?