It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

You are mixing a mixture of cement and Sand with five gallons of water. You have a garden hose giving you all the water you need. The problem is that you only have a four-gallon bucket and a seven-gallon bucket and neither has graduation marks. Find a method to measure five gallons.

What type of tree can I carry in my hand?

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

If,

1 = 5 ,
2 = 25 ,
3 = 325 ,
4 = 4325

Then, 5 = ?

How many triangles are there in the picture below?

I got a bee but no honey.
got an eye but am still blind.
got a sea but no water.
got a tea but no coffee.
got a why but no answer.

What Am I?

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

Can you find a flaw in this statement?