What is the word or phrase?

Pronounced as 1 letter, And written with 3, 2 letters there are, and 2 only in me. I’m double, I’m single, I’m black blue and grey, I’m read from both ends, and the same either way. What am I?

Count the number of triangles in the picture below:

Spot 5 differences in two Christmas tree below:

Can you count the number of seconds in a year?

Clue: You need to bother about calculation.

What word is represented by this rebus?

The barber of Town shaves all men living in the town. No man living in the town is allowed to shave himself. The barber lives in that town. Who then shaves the barber of the town?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

If,
9 * 8 * 7 = 65
8 * 7 * 6 = 50
7 * 6 * 5 = 37

Find
6 * 5 * 4 = ?

What is harder to catch the faster you run?