Using four sevens (7) and a one (1) create the number 100. Except for the five numerals, you can use the usual mathematical operations (+, -, x, :), root and brackets ()

The Little ant seems to be always confused. Do you know why?

How many people must be gathered together in a room, before you can be certain that there is a greater than 50/50 chance that at least two of them have the same birthday?

I cannot talk, but I always reply when spoken to. What am I?

Our product and our sum always give the same answer. Who are we?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

Find out the missing number in the picture attached:

A new clothing store has a unique method of pricing items. A vest costs $20, a tie costs $15, a blouse costs $30, and underwear costs $45. How much would pants cost?

A bomb exploded in a room full of married couples and no one died. How?

who is silent in the parliament?