A quantity x varies inversely as the square of y. Given that x = 4 when y = 3, the value of x when y

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22 Jan 2010 sum of ab, bc, ca ?

A quantity x varies inversely as the square of y. Given that x = 4 when y = 3, the value of x when y = 6 is

OPtion

1) 3
2) 2
3) 1
4) 4
5) 5
6) 6
7) 7
8) 8
9) 9
10)None of these

Solution

x ~ 1/y^2 => x = k/y^2, where k is constant
When y = 3 and x = 4
we have 4 = k/9 or k = 36
Therefore x = 36/y^2 thus
when y = 6
we get x = 36/6^2
= 1

Correct Option: 3 Best Solution (1)