I have teeth but i don't bite. Who Am I ?

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 ?

What begins with T, ends with T, and has T in it?

Can you replace the question mark with the correct number?

You measure my life in hours
I serve you by expiring
I vanish faster when I am thin
and slower when I am thick
The wind is my energy
What am I?

Using Only Five 5's and any mathematical operator make sum as 37

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

I have a five and a three-gallon jar. Assuming there is an infinite supply of water, how can I measure one-gallon water?

Can you find the odd number in the following?

2716, 4135, 5321 and 7145

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?