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

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

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

You have a roll of cloth 1km long. You have a machine which cuts this roll into pieces of 10-meter-long cloth.

How long would it take for the machine to cut the roll if each cut took 4 secs?

In case you were starting to feel confident, this one was meant for third graders in Vietnam. The answer is 66, but we don't blame you for scratching your head about how they got there.

Can you solve below mathematical equation?

2^1234 - 2^1233

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

Find three numbers such that When we multiply three numbers, we will get the prime numbers. The difference between the second and the first number is equal to the third and second.

In a stable, there are men and horses. In all, there are 22 heads and 72 feet. How many men and how many horses are in the stable