You need to arrange three 7 and mathematical symbols to form number 1?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

You have $100 with you and you have to buy 100 balls with it. 100 is the exact figure and you can't go below or above the numbers and you have to use the entire $100. If there is no kind of tax applied how many of each of the following balls will you be able to buy:

Green Balls costing $6
Yellow Balls costing $3
Black Balls costing $0.10

Now, how many of each must you buy to fulfil the condition given?

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 ?

There once were seven dwarfs who were all brothers. They were all born two years apart. The youngest dwarf is seven years old. How old is his oldest brother?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

A girl has as many brothers as sisters, but each brother has only half as many brothers as sisters. How many brothers and sisters are there in the family?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?