Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

What runs around the whole yard without moving?

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

Can you find the largest Three-digit number whose sum is 14 and whose square is less than 5,00,000?

There is a unique number which when multiplied by any number from 1 to 6, we will get the new number that contains the same digits only.

Can you find that number?

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=

There are three Athletes (John, Tarun and Harish) and their individual Coaches (Jacob, Meenaxi and Priyanka) standing on the shore.
No Coach trusts their Athlete to be near any other Coach unless they are also with them.
There is a boat that can hold a maximum of two persons.
How can the six people get across the river?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

In my garden, I have many trees but only one of them is the mango tree. In these mango trees, there are some mangoes(as expected).

But after a strong wind, there are neither mangoes on the tree nor on the ground. Explain?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?