Maths Challenge Answers

Tom asked his Granny how old she was. Rather than giving him a straight answer, she replied:

"I have 6 children, and there are 4 years between each one and the next. I had my first child (your Uncle Peter) when I was 19. Now the youngest one (Your Auntie Jane) is 19 herself. That's all I'm telling you!" 

How old is Tom's Granny?

Tom's Granny is 58 years old. Let's see why:

First child born: Granny is 19

Second child born: Granny is 23 (19 + 4)

Third child born: Granny is 27 (23 + 4)

Fourth child born: Granny is 31 (27 + 4)

Fifth child born: Granny is 35 (31 + 4)

Sixth child born: Granny is 39 (35 + 4)

Sixth child is 19: Granny is 58 (39 + 19)