What is always in front of you but can’t be seen?

If a boy blows 18 bubbles,
Then pops 6 eats 7 and then
He pops 5 and blows 1.
How many are left?

What does this mathematical rebus means ?

Can you make a six-letter word using the letters N, A and B ?

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

We have arranged an array of numbers below. What you have to do is use any kind of mathematical symbol you know excluding any symbol that contains a number like cube root. You can use any amount of symbols but you have to come up with a valid equation for all of them.

0 0 0 = 6
1 1 1 = 6
2 + 2 + 2 = 6
3 3 3 = 6
4 4 4 = 6
5 5 5 = 6
6 6 6 = 6
7 7 7 = 6
8 8 8 = 6
9 9 9 = 6

I get hot but I never sweat,
I cook food but I am not a chef,
I have a door but you can't enter me,
I have a light but I am not a lamp.
Who am I?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?