It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

If,

6 / 7 = 2
3 / 9 = 7
8 / 2 = 6

Then

4 / 5 = ?

Can you find a five letter word that is left with only two letters if one is removed?

The Judge knows that Alamgir was killed by his girlfriend Jasline, but the judge is unsure whether to punish her. Why?

what does the below rebus means?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

Doctor Alex and a bus driver John are both in love with the same woman named Olivia. The bus driver need to go for a long trip of 10 days, Before he left he gave Olivia 10 apples.

Which Travels Faster? Solve below famous picture riddle: