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If 6 : x : : x : 24, then x equals
A10
B18
C12
D14
Answer & Solution
Correct answer: C. 12
1. In a proportion a : b :: b : c, b is the mean proportional and b^2 = ac.
2. Here b = x, a = 6, c = 24.
3. So x^2 = 6 * 24 = 144.
4. x = 12 (positive root).
_Source: ICAI BoS Foundation Paper 3, Ch 1 Unit II 'Proportions', p.7 mean proportional_
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