Mathematics for IGCSE & O level - Proportion (Section 3 - No. 21)
If 'y' varies inversely with the square root of 'x', and x = 4 when y = 3, then when x = 9, y =?
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Пояснення
y = k / sqrt(x), so 3 = k / sqrt(4), therefore, k=6; now, 6/sqrt(9) = 2