Can you find the odd number in the following?

2716, 4135, 5321 and 7145

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

What do you see in the image below

John speaks the truth only once a day in a week. Below are a few hints for you:

First: Days are Sunday, Monday and so on.
Second: One day he says, "I lie on Monday and Tuesday".
Third: On the next day, he says, "Today is either Thursday, Saturday or Sunday".
Fourth: On the next day, he says, "I lie on Wednesday and Friday".

Can you identify the day on which he speaks the truth?

You want to boil a two-minute egg. If you only have a three-minute timer (hourglass), a four-minute timer and a five-minute timer, how can you boil the egg for only two minutes?

In a football game, Christina defeated Teresa by 2 - 0 but no man from either side scored. How can this be possible?

Can you count the number of squares in the given picture?

Find the next number in the series below

21 32 54 87 131 ?

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?