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Five years ago, Anthony was three times as old as his sister. Now he is only twice as old. How old are Anthony and his sister?
Answer
Anthony is 20 and his sister is 10. Five years ago he was 15 and she was 5.Hide Answer Show Answer
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Five years ago, Anthony was three times as old as his sister. Now he is only twice as old. How old are Anthony and his sister?
let a represent Anthony's age, then s represent the sister
First Statement:
a - 5 = (s - 5) * 3
a = (s - 5) * 3 + 5
Second Statement:
a = s * 2
Combination:
2s = (s - 5) * 3 + 5
2s = (s - 5) * 3 + 5
2s = 3s - 10
-s = -10
s = 10
Therefore, Anthony's age is 20 and his sister's is 10.
let a represent Anthony's age, then s represent the sister
First Statement:
a - 5 = (s - 5) * 3
a = (s - 5) * 3 + 5
Second Statement:
a = s * 2
Combination:
2s = (s - 5) * 3 + 5
2s = (s - 5) * 3 + 5
2s = 3s - 10
-s = -10
s = 10
Therefore, Anthony's age is 20 and his sister's is 10.
Thanks Sane... I messed up my own figures for how to do that and ended up substituting in instead >.
I just thought it through in my head. I have seen one similar to this before.
hummm... :?
Ha ha..i guessed and got it right!
I m not sure that this 1 would be in the math catergory... i don't no y, but I dont think this is the appropriate catergory for this teaser.
we did millions of these in my math class this year so i got it right away
nice teaser
yoshinode-i guess this could be in the logic category, but i think it belongs in the the category it's in
nice teaser
yoshinode-i guess this could be in the logic category, but i think it belongs in the the category it's in
That was on my eighth grade mat test, when we were supposed to use variables. So, I got it
Everyone seems to have gotten the answer right, so what is the Correction?
I would get only partial credit. Too eager to find the answer.
I would get only partial credit. Too eager to find the answer.
Just gotta be methodical, raising the sister's age by 1 every attempt.
Fun, easy and entertaining teaser; I got this one very quickly.
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