Quantitative Aptitude • Ratio, Average & MixtureMedium
What is the mean proportional between 144 and 36?
A. 76
B. 144
C. 72✓ Correct Answer
D. 90
💡 Solution & Explanation
The mean proportional between two numbers a and b is √(a × b). Here √(144 × 36) = √5184 = 72. Check: 144 : 72 = 72 : 36, because 144 × 36 = 72 × 72 = 5184. The average (90) is a different idea.
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