I make two people out of one. What am I?

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 welcome the day with a show of light, I stealthily came here in the night. I bathe the earthy stuff at dawn, But by noon, alas! I'm gone.

A bomb goes off.
Carnage.
One person, only a few feet away, survives! How can this be?

In a school, 280 students studied chemistry, 254 students studied physics and 280 students studied biology.

97 students studied chemistry as well as physics, 138 students studied physics as well as biology and 152 students studied chemistry as well as biology.

73 students studied all the three branches.

Can you find out the total number of students?

A man desired to get into his work building, however he had forgotten his code.
However, he did recollect five pieces of information
* Fifth number + Third number = 14
* The fourth number is one more than the second number.
* The first number is one less than twice the second number.
* The second number and the third number equals 10.
* The sum of all five numbers is 30.

What is the code ?

In the four images below, can you find the odd one out?

How high do you have to count before you use the letter “a” in the English spelling of the whole number?

Find the mistake in the below maths equations

A = 2
A(A-1) = 2(A-1)
A2-A = 2A-2
A2-2A = A-2
A(A-2) = A-2
A = 1

Identify the next two numbers in this series.

101, 112, 131, 415, 161, 718, ???, ???