Maths Homework Help

[rockyracoon]

Please God, can someone help with my daughters homework.

The HCF of 2 numbers is 6. The LCM of the same two numbers is 72.
What are the numbers?

I'm twisted and my head hurts.

Please help :)

[fiction-factory]

Yes, we should have reached for a pen and paper and drawn a Venn diagram

[rockyracoon]

Many thanks for you comprehensive answer Jim. It went totally over my head but littlun seemed to make sense of it.

Thanks again to you all. Who'd have thought that a maths question would cause such debate. ;)

[jim360]

Glad to hear rr -- also I'd suggest to your daughter that the ask the teacher if they'd accept the solution (6,72), and if not why not.

[rockyracoon]

I doubt she'd ask Jim. I will though ;)

I'll let you know what they say

[Jackdaw33]

I'm no expert, but isn't this a bad question? If the HCF of two numbers is 6 then the other number must be a multiple of 6. The answer has to be 72, because the lowest common multiple of 6 and 12 is 72. LCM means the lowest number you can get by multiplying two numbers together.

[fiction-factory]

Not necessarily, Jackdaw. e.g. the LCM of 4 and 8 is 8 not 32

[fiction-factory]

LCM of two numbers is the lowest multiple of the two numbers.

[fiction-factory]

I can't believe I've allowed myself to get drawn into this again!

[fiction-factory]

I'm not sure where 16 comes from, divebuddy? Does it refer to my example at 18:46? 16 is a multiple of 4 and 8 but it's not the lowest common multiple

[fiction-factory]

Yes, because I was replying Jackdaw33's post immediately before mine
where it was suggested "LCM means the lowest number you can get by multiplying two numbers together". So i gave an example of 4 and 8 which when multiplied give 32, but the LCM is only 8

[Jackdaw33]

It might help is someone could give the accepted definition of the term LCM.

[fiction-factory]

It has been given in the thread- I think Prudie and jim360 have both defined it if you want to look back

[fiction-factory]

Almost, divebudy - they are 8,16 and 24. The lowest common multiple of 4 and 8 is 8

[Jackdaw33]

There is a finite way of multiplying two numbers together to reach 72

1 x 72
2 x 36
3 x 24
4 x 18
6 x 12
8 x 9

Which of these is the correct answer?

[Jackdaw33]

To put it simply, the question is wrong. Unless the setter made a typo with 72 for 12, there is no logical answer.

[jim360]

Sorry, what the heck are you on about Jackdaw? I answered this completely on the previous page.