Prove that the below maths equation is true.

8 + 8 = 91

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?

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

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?

There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

Before Balboa discovered the Pacific Ocean, which was the largest ocean before that?

I know a nine-letter word having only one vowel.
Do you ?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?