Bunuel
A full glass of juice is a mixture of 20% grape juice and 80% apple juice. The contents of the glass are poured into a pitcher that is 200 percent larger than the glass. The remainder of the pitcher is filled with 16 ounces of water. What was the original volume of grape juice in the mixture?
(A) 1.6 ounce
(B) 3.2 ounce
(C) 4.8 ounce
(D) 6.4 ounce
(E) 8 ounces
To find the volume of grape juice in the original mixture, we need the volume of the glass (the volume of liquid in the glass).
TrapsThis question has two traps:
(1) "16 ounces" is relevant
only to calculation of the volume of the glass.
The added water in the pitcher does not affect the original concentration (and hence volume) of grape juice in the glass because
(a) the volume of liquid that the pitcher can hold (200% more than the glass) tells us how much the glass can hold, and
(b) the volume of liquid that the glass can hold will yield the original volume of grape juice: 20% of whatever amount of liquid was in the glass
2) 200 percent more than*?
Analogize:
-- \(10\) percent more than A: \(A = (1A + .10A)= 1.10A\)
-- The multiplier for 200 percent is 2
10 percent = \(\frac{10}{100}=.10\)
200 percent = \(\frac{200}{100}=2\)
Solve• Find the volume of the glass in terms of the volume in the pitcher
Let \(x\) = the volume of the glass in ounces
The pitcher's volume is 200 percent more than \(x\):
Pitcher: \(x + (2)(x) = 3x\)
• The equation depends on the 16-ounce volume difference
The pitcher can hold the amount in the glass plus 16 ounces of water
[Amount in glass] + 16 oz = pitcher ounces, so
\(x + 16 = 3x\)
\(2x = 16\)
\(x = 8\) ounces = volume of [liquid in] the glass
• Volume of grape juice in the original mixture?
Volume of grape juice = 20% of the original liquid's total volume of 8 ounces:
\(.20(8)=1.6\) ouncesAnswer ATranslation: 200 "percent larger than" = "percent greater than" = "percent MORE THAN"