Find out the number of circles in the given picture having Illusion

Count the number of times the letter "F" appears in the following paragraph:

FAY FRIED FIFTY POUNDS OF
SALTED FISH AND THREE POUNDS
OF DRY FENNEL FOR DINNER FOR
FORTY MEMBERS OF HER FATHER'S FAMILY.

Find the next number in the sequence

5 12 24 36 ?

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

What is full of holes but still holds water?

Find the missing number in the sequence below:

John and Jacob are twin brothers. One of them is a liar whereas the other one is a truth-teller.

I called their home number and one of them picked up.
I asked. 'Does John lie?' The person replied with a yes.

Whom did I talk with, John or Jacob?

I have Rs.50 and I spend it in the way as below.

How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?

John and his wife were living in a rural place. On a particular day, John's wife fell ill and he called the local doctor. When the doctor picked up, he said, "Doctor, my wife is ill. She might have appendicitis."

"This can't be possible! I took out her appendix two years ago myself," the doctor explained.

When diagnosed, John's wife was found to have appendicitis. How can this be possible?