Why is Saturday stronger than Monday?

You walk into a room where there are three primates held in their respective cages:
1) A lion who is eating the flesh of a goat.
2) An orangutan who is playing with blocks.
3) A donkey who is sitting idle.

Who is the most intelligent primate in the room?

Find the missing number in the image below.

Identify the 10 differences between the two given pictures.

Find the next number in the series.
1 10 24 43 67 ?

Birbal was jester, counsellor, and fool to the great Moghul emperor, Akbar.
The villagers loved to talk of Birbal's wisdom and cleverness,
and the emperor loved to try to outsmart him.
One day Akbar (emperor) drew a line across the floor.
"Birbal," he ordered, "you must make this line shorter, but you cannot erase any bit of it."
Everyone present thought the emperor had finally outsmarted Birbal.
It was clearly an impossible task.
Yet within moments the emperor and everyone else present had to agree that Birbal had made the line shorter without erasing any of it.
How could this be?

Solve the puzzle by telling what does below picture means.

Can anyone tell me a word in the English dictionary which has a silent 'z'?

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

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