Question 601630: Harry is older then 10. His age this year is a square number, in two years time his age will be a multiple of 11. How old is Harry?
Answer by godsgirls(5)   (Show Source):
You can put this solution on YOUR website! Well, we know he is over ten, and his age is a square number. start listing square numbers over ten.
16 = 4 squared
25 = 5 squared
36 = 6 squared
49 = 7 squared
64 = 8 squared
81 = 9 squared
100= 10 square
I seriously doubt Harry is older than 100, so we'll stop here.
Now, which of these numbers, if you add two, can be divided by eleven? Well, start adding two to all your squared ages.
Is it 18? 27? 38? 51? 66? 83? or 102?
it should be easy to see that 66 is the only number divisible by 11. Before we added two, it was 64. Harry is 64 years old.
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