Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

I am a number I am not an odd number I am higher than 90 I am not higher than 100 If you subtract me from 100, you get nothing. What number am I?

Spot 5 differences in two Christmas tree below:

If you had an infinite supply of water and 5-quart and 3-quart pails, how would you measure exactly 4 quarts? What is the least number of steps you need?

Which five letter word can be added at the end of below word to form a
valid word?

> Pin
> Check
> Boiling
> View

Can you count the number of seconds in a year?

Clue: You need to bother about calculation.

Arrange the numbers 1, 2, 3, 4, 5, 6, 7, 8 and 9 above and below the division line in a manner that the thus formed fractions equal to 1/3.

(You can use one number only once)

Can you make a six-letter word using the letters N, A and B ?

Look at the picture and find out which square is not linked with any of the other squares.

Find the missing number in the series below

13 -21 34 -55 ? -144