Can you find the odd number in the following?

2716, 4135, 5321 and 7145

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?

Count the squares in the matchstick puzzle below?

A network of 20 x 10 squares is given to you.

Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?

What brings you down but never up?

Two old friends, Jack and Bill, meet after a long time.

Three kids
Jack: Hey, how are you, man?
Bill: Not bad, got married and I have three kids now.
Jack: That's awesome. How old are they?
Bill: The product of their ages is 72 and the sum of their ages is the same as your birth date.
Jack: Cool..But I still don't know.
Bill: My eldest kid just started taking piano lessons.
Jack: Oh, now I get it.

How old are Bill's kids?

The centre of the third figure is empty. What digit should fit inside?

Out of four images which one is the odd one out?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

What number do you get when you multiply all of the numbers on a telephone's number pad?