If 21x = 79x, what is the value of x?

Move three sticks of the spiral below to form a square.

What does man love more than life, and hate more than death or mortal strife; that which satisfied men want; the poor have, and the rich require; the miser spends, the spendthrift saves, and all men carry to their graves?

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

What is common among 11, 69, and 88?

Can you solve this tricky maths equation problem by replacing it? mark with the correct symbol?

19834 -----: 187
15921 -----: 153
17561 -----: 139
13734 -----: ???

See the given image carefully. What you have to do is move the blue checkers in the position of the black checkers and vice versa. You are only allowed to move the checker to an adjacent empty space. Do it in the least possible moves.

It can be easily calculated that the digits 0 to 9 can be arranged into 3628800 distinct ten-digit numbers.

But do you know how many of these numbers are prime?

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?