Can you replace the question mark with the correct letter?

6 + 6 + 6 = N
7 + 7 + 7 = E
8 + 8 + 8 = R
0 + 0 + 0 = ?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

As shown in the image, the nine Dogs are square fenced. By constructing just two square fences can you make sure that two Dogs cannot meet each other without crossing the fence?

See the given image carefully. What you have to do is move the blue checkers in the position of the black checkers and vice versa. You are only allowed to move the checker to an adjacent empty space. Do it in the least possible moves.

What breaks yet never falls, and what falls yet never breaks?

I have branches, but no fruit, trunk or leaves. What am I?

You see me once in June, twice in November, and not at all in May. What am I?

O_er_t_o_

Complete the missing letters of the given word.

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

Count the squares in the matchstick puzzle below?