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'Gran, How Old Are You?' printed from http://nrich.maths.org/
Mum and her four children live with Gran at 13 Drywater
One day, Charlie, who is the third child, asked, "Gran, how old are
Gran answered, "My Grandmother would have said 'As old as my tongue
and a little older than my teeth!' but I will tell you how to work
out my age."
"If you multiply Mum's age with your age and with the ages of your
brother and sisters you will get the answer $111 111$.
If you add Mum's age along with the ages of all you four children
the total will be my age."
Charlie worked this out very quickly, because he knew his Mum's
age, his age and the ages of his brother and sisters.
"Oh Gran!" he called as he ran off to play outside, "You are
How old was