A store sells milk in cartons of two sizes, one-half gallon and one-qu

300=x+y

1: we know y so we can figure out x. Thus we can figure out the amount of gallons

2: .5x=90 --> x=180 cartons We can find y b/c we know x


D

I'm getting different answers when I solve to prove its D can someone please provide detailed explanation with equations! thanks

Nq - Number of quarter gallon cartons sold
(300 - Nq) - Number of half gallon cartons sold

Gallons of milk sold = Nq*(1/4) + (300 - Nq)*(1/2)

1. yesterday the store sold 120 one-quarter-gallons of milk.
I assuming that they meant '120 one-quarter-gallon cartons of milk'.

So Nq = 120. So, Nh = 180
Gallons of milk sold = 120*(1/4) = 180*(1/2)


2. Yesterday the store sold 90 gallons of milk in one-half-gallon cartons.

(300 - Nq)*(1/2) = 90
300 - Nq = 180
Nq = 120

Gallons of milk sold = 120*(1/4) = 180*(1/2)

Must read the question carefully unlike I did, initially.

The store sells two size of milk cartons, one-half gallon and one-quarter gallon cartons. Yesterday, they sold 300 cartons of milk in total.

Stem: wants to know how many gallons of milk were sold, so we must be given the part to whole or part to part ratio of types of gallons sold.
Provides that:Q+H=300 cartons

1. 300 cartons=120+H
H=180, sufficient. 180*.5=90 120*.25=30
Gallons sold=120.

2.90 gallons sold in 1/2 gallon cartons, so 180 half-gallon cartons were sold. This tells us that: 300=Q+180, so Q=120 cartons. 120*.25=30 gallons
sufficient

Each statement alone is sufficient, D.

Great explanation nch2024. Couldn't get my head round why is "90 gallons of milk in one-half-gallon cartons" is not 90 but 180 ? Thanks for your time in advanced.

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