Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

Find the number of squares in the below-given picture.

A 52% bias toss for head using the 51% tail bias coin was done to obtain a fair result.

Can you find how bias is the floor in this case?

If "P" means "-", "Q" means "/", "R" means "+", and "S" means "*" then find the value of the following:

21 Q 7 R 9 S 10 P 13

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not rounded numerals equals 24.

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

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

In a competitive exam, each correct answer could win you 10 points and each wrong answer could lose you 5 points. You sat in the exam and answered all the 20 questions, which were given in the exam.
When you checked the result, you scored 125 marks on the test.

Can you calculate how many answers given by you were wrong?

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

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?