Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

A Shopkeeper sold a few chickens to four different customers on a particular day. It was such that each customer purchased half of the remaining chickens and half the chicken more.

Can you find out how many chicken were sold by the shopkeeper on that day if we tell you that the fourth customer bought a single chicken ?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

Solve the mathematical equation in the picture below.

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

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?

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

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?