Find the number of squares in the below picture

Manish has to secure 40% marks to pass his B.tech final exams.
He got just 40 marks and failed by 40-marks.

What is the maximum marks?

A father's child, a mother's child, yet no one's son.

Who am I?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

In a kingdom, King George did not allow any citizen to visit the world outside. Also, only a person with proper paperwork was allowed to enter or he was sent back. A wooden bridge was what connected the kingdom to the world. The king had appointed a sharpshooter who would check the every five minutes on the bridge to check. After checking, he would go back to his hut and return exactly after five minutes again. The bridge took 9 minutes to cross.

A merchant was able to escape the kingdom without harming the shooter. How?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

Which is the smallest number that you can write using all the vowels exactly once?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

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

A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?