Math Is Fun Forum

paulb203

Member

Registered: 2023-02-24

Posts: 136

LCM question

Q. Rita is going to make some cheeseburgers for a party.
She buys some packets of cheese slices and some boxes of burgers.
There are 20 cheese slices in each packet.
There are 12 burgers in each box.
Rita buys exactly the same number of cheese slices and burgers.
How many packets of each does she buy?

My attempt at an answer;

I’m pretty sure this is an LCM question (Lowest Common Multiple).
I started listing the prime factors for the cheese slices; 20 = 2^2 x 5
Then the burgers; 12 = 2^2 x 3
Then put the factors in a Venn diagram and found the LCM was 60
Then divided 60 by 20 for the cheese slices = 3 packets
Then divided 60 by 12 for the burgers = 5 boxes

But I’m now thinking that Rita could have bought 6 packets and 10 boxes. Or 12 packets and 20 boxes. Etc, etc.
Q. Is the question badly worded?

amnkb

Member

Registered: 2023-09-19

Posts: 253

Re: LCM question

...But I’m now thinking that Rita could have bought 6 packets and 10 boxes. Or 12 packets and 20 boxes. Etc, etc.
Q. Is the question badly worded?

yeah i think so
they should have said something like 'what is the least number'

paulb203

Member

Registered: 2023-02-24

Posts: 136

Re: LCM question

Thanks, amnkb.