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

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

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

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

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

A cricket has 6 legs, a squirrel has 4 legs and a spider has 8 legs.

In a local zoo, it was found that the total number of legs is 612. Also, there are equal number of each of the above animals/insects.

Can you find out how many animals are there in the zoo?

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 ()

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?

John went to buy some expensive, foreign chocolates. He only had Rs 100 with him. When he reached the shop, he got out and know that on those chocolates, there was a 15% import duty and 5% VAT.

How much worth chocolate should he buy so that he can accommodate it in Rs 100?

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?

Can you find out which number multiplied by itself will give the output as 12345678987654321?