A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

How high do you have to count before you use the letter “a” in the English spelling of the whole number?

A patient was diagnosed with some ailment. He was given five different tablets to take at night at an interval of 15 minutes.

How long will it take the patient to consume all the five tablets?

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

What does does this rebus picture means ?

What are the 50th, 63rd and 100th numbers in the sequence below?
4, 5, 8, 8, 9, 9, 12, 13, 13, 13, 17, 18, ...

You have two buckets - one holds exactly 5 gallons and the other 3 gallons. How can you measure 4 gallons of water into the 5 gallon bucket?

(Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.)

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 ?

I am an odd number. Take away a letter and I become even. What number am I?

If you're 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door?