2 variable question from "Ace the GMAT"

[tomslawsky]

This question is confusing me, although the answer is right there. Any input on the most efficient way to tackle it?:

A restaurant uses the same volume of chili paste weekly, which comes in either 15 or 25 oz cans. If the restaurant orders 40 more small cans than larger cans to fulfill it's weekly need, how many small cans does it order?

I don't have the book in front of me now, so I will check to make sure this is it, but I've looked at this problem for 45 mins now, so I'm pretty sure this is it. Ya, I know it's an easy question, but sometimes the easy ones throw me and I need to be able to solve this problem type, not just this problem so memorizing the answer yields marginal benefit. Thank you in advance.

[reply2spg]

is it 24?

[RB_51273]

It will be 100
Let the no of small can is X;then Larger can=x-40
Volume of the small can=15x,and larger can=(x-40)25
As same vol is used in a week
Hence
15x*7=(x-40)*25*7

Solve for X,u will get x as 100

Ram

[amar.doshi]

A restaurant uses the same volume of chili paste weekly, which comes in either 15 or 25 oz cans. If the restaurant orders 40 more small cans than larger cans to fulfill it's weekly need, how many small cans does it order?

The problem seems to be worded in a confusing manner. Do the combined cans meet the weekly need (x and 40+x); or does the restaurant order x large cans or (40+x) small cans to satisfy the same weekly volume?

If it's the latter, it's easy to solve. If it's the former then I'm guessing it's a data sufficiency question and they have given some conditions?

[imanemekouar]

Can you please this question further?

[tomslawsky]

sorry, i returned the book to the library

[RonPurewal]

This question is confusing me, although the answer is right there. Any input on the most efficient way to tackle it?:

A restaurant uses the same volume of chili paste weekly, which comes in either 15 or 25 oz cans. If the restaurant orders 40 more small cans than larger cans to fulfill it's weekly need, how many small cans does it order?

I don't have the book in front of me now, so I will check to make sure this is it, but I've looked at this problem for 45 mins now, so I'm pretty sure this is it. Ya, I know it's an easy question, but sometimes the easy ones throw me and I need to be able to solve this problem type, not just this problem so memorizing the answer yields marginal benefit. Thank you in advance.

that's a long time to look at a problem.

you'll find that the quality of many third-party materials is fairly dodgy. there's an easy explanation for this: test prep is one of the few fields in which customers, by definition, are absolutely unable to discern the quality of the material! (i.e., if someone were consistently able to determine the quality of a problem, that person would most likely not need test prep the first place)

so, this is one of the results: a shoddily written problem, albeit one that, if decoded, is a pretty decent word problem.

here's a clearer way to word this problem:
"if the restaurant fulfilled its weekly need using only small cans, it would have to order 40 more cans than if it fulfilled this need using only larger cans."

poster "RB_51273" above figured this out, although i'm not quite sure why that poster is multiplying both sides by 7.