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

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

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

A Child was born in Lahore, Pakistan. Still, the child is not a Pakistani citizen. why?

What does this simple rebus mean?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

Two guards were guarding the camp.Guard-1 was looking towards the south to make sure no threat is coming from the road.Guard-2 was looking at the north to make sure no threat is coming from the top. Suddenly Guard-1 ask the Guard-2 why he is smiling?How Guard-1 knows that Guard-2 is smiling?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

If you’ve got me, you want to share me; if you share me, you haven’t kept me. What am I?

Can you find the odd number in the following?

2716, 4135, 5321 and 7145