Combined ages question
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Combined ages question
Hi can someone help with the following:
The combined age of Alan and Ben is forty three.
The combined age of Alan and Carl is fifty five and the combined age of Ben and Carl is sixty-six.
What is the combined age of Alan, Ben and Carl?
How old is Alan?
The combined age of Alan and Ben is forty three.
The combined age of Alan and Carl is fifty five and the combined age of Ben and Carl is sixty-six.
What is the combined age of Alan, Ben and Carl?
How old is Alan?
Re: Combined ages question
If you think about these three facts and add them then you have ....The combined age of Alan and Ben is forty three.
The combined age of Alan and Carl is fifty five and the combined age of Ben and Carl is sixty-six.
Let me know if the hint isn't enough to get the first part - once you know that then Alan's age should be straight forward.
Re: Combined ages question
I added Alan and Carl (55) plus Ben and Carl (66) total 121
Then substracted Alan and Ben (43) as we had them included in the sum above:
Total 78 which is Carl's age twice, so I divided it by 2 = 39
So, Carl is 39, then you can deduct 39 from Alan and Carl's age to get Alan's = 16
Alan is 16.
You know that Ben and Carl is 66, so add 16 and you get 82 for the three.
I bet there are quicker ways of doing it and the reason I mostly leave Maths to my husband who works these problems out very quickly!
Then substracted Alan and Ben (43) as we had them included in the sum above:
Total 78 which is Carl's age twice, so I divided it by 2 = 39
So, Carl is 39, then you can deduct 39 from Alan and Carl's age to get Alan's = 16
Alan is 16.
You know that Ben and Carl is 66, so add 16 and you get 82 for the three.
I bet there are quicker ways of doing it and the reason I mostly leave Maths to my husband who works these problems out very quickly!
Re: Combined ages question
Thanks both.
Salsa - would you mind asking your husband how he would work it out? Curious to see the other possibilities also. Thank you!
Salsa - would you mind asking your husband how he would work it out? Curious to see the other possibilities also. Thank you!
Re: Combined ages question
Guest55 wrote:If you think about these three facts and add them then you have ....The combined age of Alan and Ben is forty three.
The combined age of Alan and Carl is fifty five and the combined age of Ben and Carl is sixty-six.
Let me know if the hint isn't enough to get the first part - once you know that then Alan's age should be straight forward.
Yes, this is the easy way.
A+B+A+C+B+C = 43+55+66
so you basically have 2x the combined ages 2(A+B+C) = 164 etc. and easy to get A from that
[v. similar question at the end of Kingston Grammar's maths paper last year]
Re: Combined ages question
J50 - there is no need for any algebra here - see my post
Re: Combined ages question
Ok. He did it differently and quicker.
To know the age of the three. Add all the ages and divide by two. This as you have all the ages twice.
2a+2b+2c=164
A+b+C= 82
82- (b+c) = a
82-66=16
To know the age of the three. Add all the ages and divide by two. This as you have all the ages twice.
2a+2b+2c=164
A+b+C= 82
82- (b+c) = a
82-66=16
Re: Combined ages question
Thanks all! Now I understand it