Answer:
12.
Ratios that can form a proportion with 15/8 are those that are equivalent fractions. In this case, 60/32 can form a proportion with 15/8, because they are equivalent, if we simplify 60/32 we would have 15/8, because 60/4=15 and 32/4=8.
Therefore, the right answer is C.
13.
Here we apply the same definition, a proportion is an equality between two fractions. In this case, the ratios that can form a proportion are A. 9/45, 8/40, because both fractions are equivalent to 0.2.
14.
To solve this problem, we can apply the rule of three, if 7 ounces of milk provides 236.25 milligrams of calcium, how many ounces of milf would provide 67.5 milligrams of calcium.

Therefore, the right answer is B.