How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

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

At my favorite fruit stand,
an orange costs 18,
a pineapple costs 27,
and a grape costs 15.
Using the same logic, can you tell how much a mango costs?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

There are 2 cops parked along a one-way street looking for traffic violations. They spot a taxi driver going in the wrong direction, yet they do nothing.

Why?

What can go up a chimney down, but can’t go down a chimney up?

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 ?

You see a mathematical expression in the picture. Can you think of a movie that this expression refers to?