The ratio of Arabica:Robusta:Flavoring is 5:3:2. The Robusta beans correspond to 3 parts of this ratio. Given that 750 grams of Robusta beans are used, one ratio part equals 750 grams / 3 = 250 grams. The total number of ratio parts in the blend is 5 (Arabica) + 3 (Robusta) + 2 (Flavoring) = 10 parts. To find the total weight of the coffee blend, multiply the value of one part by the total number of parts: 250 grams/part * 10 parts = 2500 grams. Why others are wrong: A — This is the weight of only the Arabica beans (5 parts * 250 g). B — This is the combined weight of Arabica and Robusta beans, excluding the flavoring agents (8 parts * 250 g). D — This would be the result if Robusta beans were mistakenly assumed to represent 2 parts of the ratio (750 g / 2 parts = 375 g/part; 375 g/part * 10 parts = 3750 g).

The ratio of apples to oranges is 3:5. The total number of parts in the ratio is 3 + 5 = 8 parts. The total number of fruits is 72. To find the value of one part, divide the total fruits by the total parts: 72 ÷ 8 = 9 fruits per part. Since oranges represent 5 parts of the ratio, multiply the value of one part by 5: 5 × 9 = 45 oranges. Why others are wrong: A — This represents the number of apples (3 parts * 9 fruits/part). B — This might result from an incorrect calculation or misinterpretation of the ratio parts relative to the total. C — Correct. D — This might result from an arithmetic error or miscalculation of the proportion.

1. The ratio of blue to yellow paint is 3:5. 2. This means there are 3 parts blue paint and 5 parts yellow paint. 3. The total number of parts in the mixture is 3 + 5 = 8 parts. 4. The total quantity of paint used is 48 liters. 5. To find the quantity represented by one part, divide the total quantity by the total number of parts: 48 liters / 8 parts = 6 liters per part. 6. Since yellow paint constitutes 5 parts, multiply the quantity per part by 5: 5 parts * 6 liters/part = 30 liters. Why others are wrong: A — This is the quantity of blue paint (3 parts * 6 liters/part). B — This represents half of the total paint, not based on the given ratio. D — This would result from an incorrect calculation, such as assuming yellow was 6 parts or a misunderstanding of the total.

1. **Determine Reference books:** The ratio of Non-Fiction to Reference books is 2:1. Since there are 120 Non-Fiction books, 2 parts correspond to 120 books. Therefore, 1 part (Reference books) equals 120 / 2 = 60 books. 2. **Determine Fiction books:** The ratio of Fiction to Non-Fiction books is 5:3. Since there are 120 Non-Fiction books, 3 parts correspond to 120 books. Therefore, 1 part equals 120 / 3 = 40 books. Fiction books (5 parts) equal 5 * 40 = 200 books. 3. **Calculate Total books:** Add the number of books in all three sections: Fiction + Non-Fiction + Reference = 200 + 120 + 60 = 380 books. Why others are wrong: A — Incorrectly assumes the combined ratio F:NF:R is 5:3:1, where Non-Fiction (3 parts) = 120, leading to a unit of 40, and a total of (5+3+1)*40 = 360. C — Incorrectly assumes the combined ratio F:NF:R is 5:3:2, where Non-Fiction (3 parts) = 120, leading to a unit of 40, and a total of (5+3+2)*40 = 400. D — Miscalculates Fiction books, possibly by interpreting the Non-Fiction to Reference ratio (2:1) as Fiction to Non-Fiction, yielding Fiction = 120 * (2/1) = 240. Then 240 + 120 + 60 = 420.

The ratio for charities A, B, and C is 2:3:5. This means Charity B receives 3 parts of the total sum. Given that Charity B receives $1,200, we can find the value of one ratio part: $1,200 / 3 = $400 per part. The total number of ratio parts is 2 (for A) + 3 (for B) + 5 (for C) = 10 parts. To find the total sum of money distributed, multiply the total number of parts by the value of one part: 10 parts * $400/part = $4,000. Why others are wrong: A — This is the sum of Charity A's and Charity C's shares (2+5=7 parts * $400 = $2,800). B — This could result from an error in calculating the total parts (e.g., assuming 9 parts instead of 10, i.e., 9 * $400 = $3,600). D — This could result from an error in calculating the total parts (e.g., assuming 12 parts instead of 10, i.e., 12 * $400 = $4,800).