A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

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

What numbers should go on the bottom line?
3 6 9 15
8 2 10 12
11 8 19 27
19 10 29 39
? ? ? ?

How many triangles are there on the puzzle below?

"That Restaurant always remains crowded. This is the reason why nobody goes there".

Can you find a flaw in this statement?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

Jack was having a candle light dinner with his girlfriend. Suddenly a cold gush of wind entered through the open window and three of the ten candles were extinguished. Assuming that none of the other candles were extinguished.

How many candles are they left with in the end ?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?