Replace the question mark with the correct number in the below-given picture?

On a certain day, John celebrated his birthday. Two days later, his older twin brother Jacob celebrated his birthday.

Is this even possible? How can it be?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

A cat had three kittens: Snophy, Topsy and Jorden. What was the mother's name?

One day, I thought of ways that can be used for creating a palindrome. So I decided that I will turn into a larger number by adding the reversed digits to the original number and keep doing it till I finally obtained a palindrome.

I am not sure if this process will always result in a palindrome eventually but I was able to produce a four-digit palindrome. Can you guess my starting number?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

You are given with the following sum. Each of the letters can be decoded as a digit. If we tell you that D = 5, then can you solve it entirely?

DONALD
+GERALD
=ROBERT

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?

I was speeding and ran through a stop sign, yet two traffic officers who were there do nothing about it.

why?