What number comes next in the series?

5 15 5 18 5 24 14 20 _

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

Why do people go to bed?

I am five letter word that is under you.
If you remove my 1st letter, then I am over you.
If you remove my 1st and 2nd letters then I am all around you.

Who am I?

What can jump higher than a building?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

Can you find the odd number in the following?

2716, 4135, 5321 and 7145

A swan sits at the center of a perfectly circular lake. At an edge of the lake stands a ravenous monster waiting to devour the swan. The monster can not enter the water, but it will run around the circumference of the lake to try to catch the swan as soon as it reaches the shore. The monster moves at 4 times the speed of the swan, and it will always move in the direction along the shore that brings it closer to the swan the quickest. Both the swan and the the monster can change directions in an instant.
The swan knows that if it can reach the lake's shore without the monster right on top of it, it can instantly escape into the surrounding forest.

How can the swan successfully escape?

I add 5 to 9 and get 2. The answer is correct, so what am I?

I have Rs.50 and I spend it in the way as below.