Replace the question mark with the correct number.

A man hijacks an aeroplane transporting both passengers(8 of them) and valuable cargo. After taking the cargo, the man demands nine parachutes, puts one of them on, and jumps, leaving the other eight behind. Why did he want eight?

Which is faster, Heat or Cold ? Explain.

Can you place three balls such that the equation shown in the picture holds true?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

John is pretty weird. He likes toffees but hates chocolates. He loves books but never reads. He likes to build his troops in an online game but does not proceed with the war. He likes to go swimming but is afraid of water.

Seeking this behaviour, can you tell whether he likes balloons and parties?

I am quite hot but become too cold if you remove the first two letters. What am I?

What goes up but never comes down?

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

John and Jenni are a married couple. They have two kids, one of them is a girl. Assume safely that the probability of each gender is 1/2.
What is the probability that the other kid is also a girl?

Hint: It is not 1/2 as you would first think.