Why do you find that most of the buildings are deprived of the 13th floor?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

Can you find out which number multiplied by itself will give the output as 12345678987654321?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?

What question can you never answer yes to?

You want to boil a two-minute egg. If you only have a three-minute timer (hourglass), a four-minute timer and a five-minute timer, how can you boil the egg for only two minutes?

I want to fill my bucket using both cold and hot water.
I have two taps for both cold and hot water. The hot water tap fills the bucket in exact 6 hours and the cold water tap fills the bucket in exact 4 hours.
I turn both of them simultaneously but I forgot to turn off another tap which removes the water out of the bucket. This tap can empty the bucket in 12 hours.

How Long will it take to fill the bucket?

A newspaper is supposed to have 60 pages, but pages 24 and 41 are missing.
Which other pages won't be there?