Question 257218
step 1 -  write an expression for this sentence:
t varies directly as the cube of r and inversely as the square root of s
We get
{{{T = kr^3/sqrt(s)}}}
step 2 - find k using the given information as
{{{10 = k5^3/sqrt(.09)}}}
we get
{{{10 = 125k/.3}}}
and then
{{{3 = 125k}}}
finally,
{{{k = 3/125}}}
step 3 - rewrite with your new k value to get
{{{T = (3/125)r^3/sqrt(s)}}}