Find the value of "?" in the ball picture Riddle below:

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

If a shopkeeper can only place the weights on one side of the common balance. For example, if he has weights 1 and 3 then he can measure 1, 3 and 4 only. Now the question is how many minimum weights and names of the weights you will need to measure all weights from 1 to 1000? This is a fairly simple problem and very easy to prove also.

No matter how little or how much you use me, you change me every month. What am I?

John can fit six large chocolate boxes or nine small chocolate boxes into a carton. How many cartons will he require to put sixty-six chocolate boxes into?

what does the below math rebus puzzle mean?

With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?

Find the next number in the series below

21 32 54 87 131 ?

Rearrange the letters in "new door" to make one word.