Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

What Deficiency does the below rebus represent?

VIT_MIN

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

Three ants are going up a hill, one behind the other. The last ant then says to the other ants, 'There is an ant behind me!'' How come?

Prove that twice of ten is the same as twice of eleven.

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

I have thought of a number that is made up by using all the ten digits just once. Here are a few clues for you to guess my number:

First digits is divisible by 1.
First two digits are divisible by 2.
First three digits are divisible by 3.
First four digits are divisible by 4.
First five digits are divisible by 5.
First six digits are divisible by 6.
First seven digits are divisible by 7.
First eight digits are divisible by 8.
First nine digits are divisible by 9.
The number is divisible by 10.

Can you find out the number ?

What does below Rebus say?

XLR8

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?