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?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

A blonde put eyeliner on her head. Why?

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?

I am white when I am dirty, and black when I am clean. What am I?

A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

Can you replace the question mark with the correct letter?

6 + 6 + 6 = N
7 + 7 + 7 = E
8 + 8 + 8 = R
0 + 0 + 0 = ?

There are 3 apples in the basket and you take away 2. How many apples do you have now?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

Who has married many women but was never married?