I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

What number comes next in the series?

5 15 5 18 5 24 14 20 _

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

A number with an interesting property:

When I divide it by 2, the remainder is 1.
When I divide it by 3, the remainder is 2.
When I divide it by 4, the remainder is 3.
When I divide it by 5, the remainder is 4.
When I divide it by 6, the remainder is 5.
When I divide it by 7, the remainder is 6.
When I divide it by 8, the remainder is 7.
When I divide it by 9, the remainder is 8.
When I divide it by 10, the remainder is 9.

It's not a small number, but it's not really big, either.
When I looked for a smaller number with this property I couldn't find one.

Can you find it?

Can you find out the remainder when 3^300 is divided by 5?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

Why do we preferably have round manhole covers and not square ones?

What's a single-digit number with no value?

Remove two matchsticks to make the below equation correct.