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

Solve the following series:
AZ, GT, MN, __, YB

A rubber ball keeps on bouncing back to 2/3 of the height from which it is dropped. Can you calculate the fraction of its original height that the ball will bounce after it is dropped and it has bounced four times without any hindrance ?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

I guess 76.8% of readers will like this riddle.

What's the least number of people should read this post?

Can you complete the sequence puzzle?

AR TA GE CA LE VI LI _

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 a seven digit number which describes itself. The first digit is the number of zeros in the number. The second digit is the number of ones in the number, etc. For example, in the number 21200, there are 2 zeros, 1 one, 2 twos, 0 threes and 0 fours.

The centre of the third figure is empty. What digit should fit inside?

John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?