What does the below rebus riddle means?

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?

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

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?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

Can you solve the below algebraic mathematical equation?

(J+O+I+N+T)3 = JOINT

Find the next number in the series below

21 32 54 87 131 ?

How can you leave a room with two legs and return with six legs?

Known by all without exception, Forever here, for your protection, Sometimes strong, sometimes weak, Right after the night I come - hot and chic. And while millions of miles away, I always get to you, I find my way. No life around could do without me, Can you guess what I might be?

If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again?