What has no start, end, or centre?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

O_er_t_o_

Complete the missing letters of the given word.

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

In the image given, you can find several triangles. Can you count them all?

Why is the Hole below a Lock?

Outside a massage parlour, there is a board that reads
"I only massage those who do not massage themselves."

Reading the above statement, does the masseur massage himself?

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?

Which is the correct shadow of the bird?

Find the next number in the sequence

5 12 24 36 ?