If c varies directly as the square root of d, and c = 14 when d = 64, find c when d = 324.

Answer 1

"c varies directly as the square root of d" means:
c=k*sqrt(d)

plug in c=14, d=64 and solve for k.

then plug in 324 for d, and you will get your answer.

Answer 2

If c varies directly as the square root of d, and c = 14 when d = 64, find c when d = 324.