15.
2500 X 15 = 37500
37500 ÷ 100 = 375
375 + 200 = 575
The answer is C.
16.
The easiest way to answer this question is by going through each answer one by one:
14:6 = 28:18
28 ÷ 14 = 2
18 ÷ 6 = 3
Since both numbers were multiplied by different numbers, we can establish that this is not a true proportion.
42:7 = 6:2
42 ÷ 7 = 6
7 ÷ 7 = 1
42:7 = 6:1
By dividing both numbers by the same number, we can establish that the answer is wrong.
2:3 = 3:2
This is obviously wrong. That is because, in ratios, the order counts. So the first 3 is more than the first 2, therefore the second number on the other side of the ratio should be more than the first.
3:5 = 12:20
12 ÷ 3 = 4
20 ÷ 5 = 4
Since both numbers were multiplied by the same number, this is a true proportion.
The answer is D.
