Try your skills with this simple math riddle.

Sally asked his grandmother: “How old are you?”

She replied: “I have 6 children and there are 4 years between each one and the next. I had my first child when I was 19. Now my youngest one is 19.”

How old is Sally’s grandma?

If you get the correct answer, share it with your friends on WhatsApp, Facebook and other social networking sites.

good but please explain