Our product and our sum always give the same answer. Who are we?

I’m tall when I’m young, and I’m short when I’m old. What am I?

Can you find the mistake in the below statement?

Two boys wish to cross a river. The only way to get to the other side is by boat, but that boat can only take one boy at a time. The boat cannot return on its own, there are no ropes or similar tricks, yet both boys manage to cross using the boat.

How?

John drives to his office at 20km/hr. After reaching the office, he realizes that today is a holiday. He went back at an average speed of 30km/hr. Discounting the time spent in the stoppage what was the average speed of his journey?

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

Why is it against the law for a man living in Delhi to be buried in Mumbai?

There is a brick of gold and a brick of iron in a boat (both 10-inch blocks), if they are both dropped into the water which will make the water level higher?

Be active and find the killer in the picture Riddle below.

A plane crashed between the border of Mexico and America. Where do you bury the survivors?