5.If 2 packages contain a total of 12 doughnuts, how many doughnuts are there in 5
packages?
A) 24
B) 30
C) 36
D) 60Here’s How to Crack It
This problem simply describes two equal ratios, one of which is missing a single piece of information.
Here’s the given information represented as two equal ratios:
Because ratios can be written so they look like fractions, we can treat them exactly like fractions. To find
the answer, all you have to do is figure out what you could plug in for x that would make = . Now
cross-multiply:
so, 2x = 60x = 30The answer is (B).
Many proportion questions will also involve unit conversion. Make sure to pay attentions to the units and
have the same units in both numerators and the same units in both denominators.
Let’s look at an example.
21.Gary is using a 3D printer to create a miniature version of himself. The scale of the
miniature is 0.4 inches to 1 foot of Gary’s actual height. If Gary is 5 feet and 9 inches
tall, what will be the height of his 3D-printed miniature? (12 inches = 1 foot)
A) 2.0 inches
B) 2.3 inches