Why is a river so rich ?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

Who is generally closer to the kids, mom or dad?

(it's a funny riddle)

A bank customer had $100 in his account. He then made 6 withdrawals. He kept a record of these withdrawals, and the balance remaining in the account, as follows:

Withdrawals Balance left
$50 $50
$25 $25
$10 $15
$8 $7
$5 $2
$2 $0
----- -----
$100 $99

Why are the Totals not tallying?

You bought me for dinner but never eat me. What am I?

I can be cracked, made, told, and played. What am I?

Different lights make me strange by changing me into different sizes. What am I?

What does a man do only once in his lifetime, but women do once a year after they are 29?

I am five letter word that is under you.
If you remove my 1st letter, then I am over you.
If you remove my 1st and 2nd letters then I am all around you.

Who am I?

What is the fastest way to double your money?