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

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

Can you fill the blank with the correct number?

6 30 870 756030 _____

Can anyone tell me a word in the English dictionary which has a silent 'z'?

Prove that the below maths equation is true.

8 + 8 = 91

By what process could you make a 'Tea-Table' into food?

An equation has been laid down using a few matchsticks. However, as you can see, the equation is not correct. Can you correct the equation if you are allowed to add or remove 5 matchsticks?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

Find the next number in the series.
1 10 24 43 67 ?