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

In a school, there are four subjects. Seventy percent of students study English, seventy five percent of students study Science, eighty five percent of students study Mathematics and eighty percent of students study Spanish.

Can you calculate the percentage of students that study all four subjects?

Can you find out the remainder when 3^300 is divided by 5?

Replace all '*' with digits 1, 2, 3, 4, 5 and 6 to make below statement true.

* *
x *
=====
* * *

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?

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

Rectify the following equality 101 - 102 = 1 by moving just one digit.