Question 157936
y varies jointly as a and b and inversely as the y = 48 when a = 4, b =8, and c = 36square root of c. What you are not told is if there are some other factors as well. Let's assume there is some other constant involved. We will call that M

So
{{{y = M *(a*b)/(sqrt(c)) }}}

You are told "y = 48 when a = 4, b =8, and c = 36"
So
{{{48 = M * 4*8/sqrt(36) }}}
{{{48 = M * 32/6}}}
{{{48*6/32 = M }}}
{{{9 = M}}}

Our final equation is
{{{y = 9 * a* b/sqrt(c) }}}

Now you are asked " Find y when a = 2, b = 7, and c = 16."

I bet you can take it from here :)