Prove that the below maths equation is true.

8 + 8 = 91

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

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?

A plane crashed between the border of Mexico and America. Where do you bury the survivors?

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

A tourist visits a small town for his research. While in the town, he decides to get a haircut. Since the town is quite small, there are only two barbers in the town � one on the North Street and one on the South Street. The barbershop on the North Street is a mess and the barber has a weird and pathetic haircut. While the barbershop at the South Street is pretty tidy and the barber as well has an impressive haircut.

Which barbershop will the tourist visit for his haircut and why?

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

You and your two friends are working in a multinational company. How can you three find out the average salary of you all without disclosing your own salary to the other two?

Alex opened 24 presents
Jonah opened 8 presents
Clara opened 1 present

Can you find out how many presents were opened by Candy?