AHA- this where the wall lies between the knowledge and thinking described by Brian recently /kudos!
Purchase at Deli B is already set as expensive by its nature, note the price difference for every item of cheese. However, if we the buy the cheapest cheese at Deli B and the most expensive at Deli A it can be also that our shopping makes difference between two delis (common, we do it daily )

so ratio in st(2) for A, in which we are primarily interested, was set 6:2:1 to suggest that we will buy 6 units of $15 priced cheese and 2 units of $17 priced cheese and 1 unit of the most expensive cheese at $19. What else we have already set our purchase to be at the least expensive shopping made at Deli A. At Deli B what ever we purchase will be more expensive now, because even if we purchase all 6 kg. of cheese 16 dollar we should spend 96 dollars which is more than 4*$15 + 4/3 *$17 + 2/3 *$19 = $ 95.33 which is less than $96

sal_xcool wrote:--------------Deli A | Deli B
American: $15/kg | $16/kg
Provolone: $17/kg | $18/kg
Swiss: $ 19/kg | $20/kg



Julian bought 6 kilograms of cheese from each Deli A and Deli B. At which deli did he spend more money on cheese?

1. The ratio of American to Provolone to Swiss purchased at Deli B was 2:7:2
2. The ratio of American to Provolone to Swiss purchased at Deli A was 6:2:1

OA B


When I looked at this question, I immediately chose C, thinking that I need to know how much he purchased at each Deli shop.

Assuming that the answer is B, how can you tell that Julian spent less or more money in Deli B?
he spent [spoiler](6*15)+ (2*17) + (1*19) = $143[/spoiler] total at Deli A.

I really need help to understand this. Thank you for your comments.

sal_xcool wrote:-
Julian bought 6 kilograms of cheese from each Deli A and Deli B. At which deli did he spend more money on cheese?

1. The ratio of American to Provolone to Swiss purchased at Deli B was 2:7:2
2. The ratio of American to Provolone to Swiss purchased at Deli A was 6:2:1

OA B



Assuming that the answer is B, how can you tell that Julian spent less or more money in Deli B?
he spent [spoiler](6*15)+ (2*17) + (1*19) = $143[/spoiler] total at Deli A.

He only bought 6 kilos of cheese - according to your formula, he bought 9 kilos, which is why your numbers don't work out.

We know the ratio at Deli A is 6:2:1, so there are a total of 9 parts. Since 9 parts = 6 kg, 1 part = 6/9 = 2/3 of a kg.

So, he bought:

6(2/3) = 4kg of American
2(2/3) = 4/3 kg of Provolone
1(2/3) = 2/3 kg of Swiss

Accordingly, he spent:

4*15 + 4/3(17) + 2/3(19) = 60 + 68/3 + 38/3 = 60 + 106/3 = 60 + 35 1/3 = $95 1/3

at Deli A.

Now, even if he had bought 6 kilos of the cheapest cheese at Deli B, he would have spent:

6*$16 = $96.

Therefore, regardless of what cheeses he bought at Deli B, he definitely spent less at Deli A - sufficient!