If a ratio is 3:4 and the total parts are 28, how many parts are the second ratio?

If a ratio is 3:4 and the total parts are 28, how many parts are the second ratio?

• A. 12
• B. 16
• C. 20
• D. 8

Answer: (B)

The idea is to treat the ratio as a way of splitting the total into equal parts. A 3:4 ratio means there are 3 parts for the first quantity and 4 parts for the second, for a total of 3 + 4 = 7 equal parts. Since the whole is 28 parts, each part is 28 ÷ 7 = 4. The second quantity corresponds to 4 parts, so it is 4 × 4 = 16. Therefore, the second ratio part is 16. The other numbers would come from counting a different number of parts (for example, 3 parts would give 12, 2 parts would give 8, 5 parts would give 20), but the second part uses 4 parts.

The idea is to treat the ratio as a way of splitting the total into equal parts. A 3:4 ratio means there are 3 parts for the first quantity and 4 parts for the second, for a total of 3 + 4 = 7 equal parts. Since the whole is 28 parts, each part is 28 ÷ 7 = 4. The second quantity corresponds to 4 parts, so it is 4 × 4 = 16. Therefore, the second ratio part is 16. The other numbers would come from counting a different number of parts (for example, 3 parts would give 12, 2 parts would give 8, 5 parts would give 20), but the second part uses 4 parts.