What is the Surname of Barbie Doll?

I go up and I go down.
I go up towards the beautiful sky and down toward the green ground.
I am present tense.
I am past tense too
Children love me.

Who Am I?

Can you find the largest Three-digit number whose sum is 14 and whose square is less than 5,00,000?

There was a competition where the contestants had to hold something. At the end of the event, the winner was a person who had no hands or feet. What was it that the contestants had to hold?

f you were running a race, and you passed the person in 2nd place, what place would you be in now?

Which English verb becomes past tense just by rearranging the letters?

What is the next number in the series?

15 29 56 108 208 ?

You have 10 balls with you. A friend of yours out of nowhere asks you to place those ten balls in five lines such that each of the lines has exactly 4 balls on them. He needs to check your intelligence. Prove him by doing the task.

You are given four tennis balls and asked to arrange those balls in a manner that the distance between each one of them is exactly equal. How will you do it?

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