A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

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

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

Eight of us go fourth, not back, to protect our king from an attack. What are we?

The doctor advised his patient to take a tablet after every fifteen minutes. He gave him five tablets in total.

How much time will he take to have all the five tablets?

If one and a half boys, eat one and a half burgers in one and a half hours.

How many burgers can 9 boys eat in 3 hours?

An artist while painting a scenic beauty, decides to paint three layers of blue colour on the sky.

Which layer will go on the first?

In a Society, there are over 100 flats.

Flat 1 is named the first flat.
Flat 2 is named the second flat.
Flat 3 is named the third flat. And So On.....

A visitor decides to walk through all the flats, and he finds all the flats except flat 62.
Anmol later founds that the locals of the town have given it another name.

What is the name of the Flat?

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