Foundation Mathematics Primary 6 Ratio

Find the missing number: 3 : 8 = 15 : ___

A 20
B 24
C 40
D 45
Show Worked Solution

Worked Solution

Step 1: Find the scale factor.\n 15 ÷ 3 = 5\n (The first term was multiplied by 5.)\n\n Step 2: Apply the same scale factor to the second term.\n 8 × 5 = 40\n\n Step 3: Answer: 3 : 8 = 15 : 40\n\nVerification: Simplify 15 : 40 → GCD = 5 → 3 : 8 ✓ Answer: 40

Correct answer: 40

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