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

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

If two fifty-foot ropes are suspended from a forty-foot ceiling that is twenty feet apart, how much rope will you be able to steal if you have a knife?

Can you name some countries which do not have the alphabet 'A' in them?

What makes this number unique: 8,549,176,320?

Find the next number in the sequence

1, 2, 6, 21, 88, __?

Before the start of the car race, John and Jacob have the same amount of fuel in their car. With this fuel, John can drive for 4 hours while Jacob can drive five hours.
After a time they realize that the amount of fuel left in John's car is 1/4th of the fuel in Jacob's.

For how long they are racing?

I am never scared but became petrified and can’t live in a house but would die to make one. What am I?

How do you go from 98 to 720 using just one letter?

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?