If you go to the movies and you're paying, is it cheaper to take one friend to the movies twice, or two friends to the movies at the same time?

Can you decipher these quotes by Albert Einstein?
Blf xzm mvevi hloev z kilyovn lm gsv ovevo lm dsrxs rg dzh xivzgvw.

If your uncle’s sister is not your aunt, what relation is she to you?

Find the missing number in the sequence below:

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

Can you count the number of squares in the figure below?

John and Jill are madly in love with each other. To remind Jill of his pure love, John wants to send her a ring by post but in their country where burglary is quite prominent, any package that is not locked comes under the risk of being stolen for the contents.

John and Jill possess many padlocks but neither one of them has the other key.

Can you find a way John can send the ring to Jill safely?

If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again?

What's a single-digit number with no value?

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"