Arithmetichard · Past Paper

The ratio of third proportional to 12 and 30 and the mean proportional between 9 and 25 is:

A5:1
B1:5
C75:15
Da and c both

✓ Correct Answer: Da and c both

Third proportional (12, 30): 30^2/12 = 900/12 = 75. Mean proportional (9, 25): sqrt(9*25) = 15. Ratio 75:15 = 5:1. Both are correct.

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