Can you fill the blank with the correct number?

6 30 870 756030 _____

A man dies of old age on his 25 birthday. How is this possible?

What 5-letter word typed in all capital letters can be read the same upside down?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

There are nine letters in the below-given diagram. You have to form a nine-letter word using these letters.

What does this below rebus puzzle mean?

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

A spy was in Canada trying to steal insider information on how to set up new Maple Syrup factories in their country. He was introduced to the operations manager of the biggest factory in Canada. However, the manager was suspicious and decided to test him with a question before he trusted him. So he asked, “What would you be sure to find in the middle of Toronto?” The spy thought fast and came up with an answer for the manager. What was his answer?

The following alphametic has only one solution. Can you find it?
ENLIST + SILENT + LISTEN = ANAGRAM

PS: You may start the number from 0.

In the below-given picture of a pretty girl, there is something wrong. Can you find out what it is?