Where do you go to learn how to make ice cream?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

If you paint a brown house white it will become a white house. If the stoplight changes from red to green, then the light is green. So, if you throw a white shirt into the Red Sea, what will it become?

How many triangles are there on the puzzle below?

I’m tall when I’m young, and I’m short when I’m old. What am I?

Before the start of the car race, John and Jacob have the same amount of fuel in their car. With this fuel, John can drive for 4 hours while Jacob can drive five hours.
After a time they realize that the amount of fuel left in John's car is 1/4th of the fuel in Jacob's.

For how long they are racing?

Here is what you have to do. You have to throw a ball as hard as you can but it must return back to you even if it does not bounce at anything. Also, you have nothing attached to the ball. There is no one on the other end to catch that ball and throw it back at you.

How will you do it?

What is the Surname of Barbie Doll?

Replace the question mark with the correct number below.

You can hear me, but you can't touch or see me.

What am I?