What is the word or phrase?

Two boys wish to cross a river. The only way to get to the other side is by boat, but that boat can only take one boy at a time. The boat cannot return on its own, there are no ropes or similar tricks, yet both boys manage to cross using the boat.

How?

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

When you stop to look, you can always see me. But if you try to touch me, you can never feel me. Although you walk towards me, I remain the same distance from you. What am I?

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

Count the number of triangles in the below picture?

Can you solve the maths in the below-given picture equation?

That attorney is my brother, testified the accountant.

But the attorney testified he didn't have a brother.

Who is lying?

What Time Should the last watch show in the below figure?