Ratios and Proportions - 2 questions

[barira1]

1. In the dining room of a children´s summer camp, a quart of milk can serve 4 campers or 3 staff members are served, how much milk, in quarts, will remain unused if 16 quarts are brought into the dining room?

Ans : 2

2. A parsec is approximately 3.26 light-years, or 19.2 trillion miles. Approximately how many trillion miles are equivalent to 1 light-year?

Ans: 6

Dont have options of this question , just know the answers
Can someone solve this ?

[heshamelaziry]

i am not sure if the first question has sufficient information ? without knowing how many children and staff are in the room, I don't think this is a good question.

[Stuart@KaplanGMAT]

i am not sure if the first question has sufficient information ? without knowing how many children and staff are in the room, I don't think this is a good question.

There's definitely part of a sentence missing.

1. In the dining room of a children´s summer camp, a quart of milk can serve 4 campers or 3 staff members [....] are served, how much milk, in quarts, will remain unused if 16 quarts are brought into the dining room?

The brackets should be filled in with something like:

"If x campers and y staff members".

Based on the answer choice, we can play the "predict the question" game!

2 quarts are left over, so 14 quarts are used up.

Each camper uses 1/4 of a quart and each staff member uses 1/3 of a quart, so:

C/4 + S/3 = 14

mutliplying both sides by 12 we get:

3C + 4S = 168

I'm going to guess: 40 campers and 12 staff members!

(There are lots of possible solutions, but whatever the numbers actually are, you just plug them into the C/4 + S/3 equation to calculate the amount of milk used, then subtract that from 16 to determine how much milk is left over.)