What does this below rebus puzzle mean?

Which English verb becomes past tense just by rearranging the letters?

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?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

Count the number of triangles in the below picture?

Can you divide the below-given shape into four equal and identical pieces?

Prove that the below maths equation is true.

8 + 8 = 91

Can you identify if it's a murder or a suicide ?

You are a thief and you are being punished for your crime. People have tied your head down on a tree with a rope that has been anchored in the ground. A candle is burning below the rope which is slowly burning it away. Just below your head, a Lion has been left loose and is waiting for you to drop down on the ground so he can have you as his lunch.

You have to survive the scenario. How will you do it?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?