The capacity of an automobile cooling system is 16 quarts. It is half full of a 15% antifreeze solution. The owner is adding 2 gallons of a 90% solution (remember, 1 gallon = 4 quarts). When he is finished, what will the solution's percentage value be?

5.25%
37.5%
52.5%

Question

The capacity of an automobile cooling system is 16 quarts. It is half full of a 15% antifreeze solution. The owner is adding 2 gallons of a 90% solution (remember, 1 gallon = 4 quarts). When he is finished, what will the solution's percentage value be?


5.25%
37.5%
52.5%

ja1 · Answer

Okay so let us solve them one by one, first let's find out the percentage of the first half, so to do this we use x * 8 (since half of 16 is 8)

ja1 · Answer

So "x" would be 0.15 (for 15%) in this case.

ja1 · Answer

So plug it in and solve.

anonymous · Answer

1.2??

ja1 · Answer

Yes so out of those 8 quarts 1.2 is a concentrated anti freeze, now do the same for the other 8 quarts.

anonymous · Answer

All the question you post share a common formula.

anonymous · Answer

yeah im not guetting half the stuff tho

anonymous · Answer

i dont know dood

ja1 · Answer

Same formula:

0.90 * 8 (since 2 gallons is 8 quarts)

anonymous · Answer

so 7.2

ja1 · Answer

Eaxactly now add those two together:

1.2 and 7.2

anonymous · Answer

8.4

ja1 · Answer

Yes perfect, now divide 8.4 by the full 16 quarts.

anonymous · Answer

so 5.25%

ja1 · Answer

Yes and since we know 8.4 is around 50% of 16 we can move the 2 over the decimal and make 52.5%