Which is the smallest number that you can write using all the vowels exactly once?

Can you divide numbers from 1 to 9 (1 2 3 4 5 6 7 8 9) into two groups so that the sum of the numbers of each group is equal?

Note: 9 cannot be turned over to make it 6.

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

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

You have $100 with you and you have to buy 100 balls with it. 100 is the exact figure and you can't go below or above the numbers and you have to use the entire $100. If there is no kind of tax applied how many of each of the following balls will you be able to buy:

Green Balls costing $6
Yellow Balls costing $3
Black Balls costing $0.10

Now, how many of each must you buy to fulfil the condition given?

Complete the table series riddle by finding the number that can replace "??".

Why is a river so rich ?

Replace the question mark in the picture below.

What is the next number in this series?

4,12,84,3612....

Can it be possible to build a house that has all its four walls facing towards the South?