If P varies inversely as the square root of q, where p = 3 and q = 16, find the value of q when p = 4.
-
A.
12 -
B.
8 -
C.
9 -
D.
16
Correct Answer: Option C
Explanation
(p propto frac{1}{sqrt{q}})
(implies p = frac{k}{sqrt{q}})
when p = 3, q = 16.
(3 = frac{k}{sqrt{16}})
(k = 3 times 4 = 12)
(therefore p = frac{12}{sqrt{q}})
when p = 4,
(4 = frac{12}{sqrt{q}} implies sqrt{q} = frac{12}{4})
(sqrt{q} = 3 implies q = 3^2 )
(q = 9)
There is an explanation video available below.