Which proportion can be used to find 65% of 90?

• A. 100/65 × 90
• B. 65/90 × 100
• C. 90/65 × 100
• D. 65/100 × 90

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the problem. The goal is to find 65% of 90. In percentage problems, 'of' typically means multiplication, and percentages are expressed as fractions or decimals.
2. Step 2: Recall the formula for calculating a percentage of a number. To find x% of a number y, the formula is: \( \frac{x}{100} \times y \).
3. Step 3: Substitute the given values into the formula. Here, x = 65 (the percentage) and y = 90 (the number). The formula becomes: \( \frac{65}{100} \times 90 \).
4. Step 4: Compare the given options to the formula. The correct proportion that matches \( \frac{65}{100} \times 90 \) is the last option: \( 65/100 \times 90 \).
5. Step 5: Verify the reasoning. The other options do not correctly represent the calculation for finding 65% of 90. For example, \( 100/65 \times 90 \) and \( 90/65 \times 100 \) do not align with the percentage formula.