If Courtney has 14 hits out of 50 at bats, how many hits must she get in her next 50 at bats to finish with a .300 average?

Can someone me with this problem . show your work .

If f(x)=x+7 and g(x)=1/x what is (fog)(x)

The volume of a spherical hot air balloon v(r) = 4 3 ? r3 changes as its radius changes. the radius is a function of time given by r(t) = 3t. find the instantaneous rate of change of the volume with respect to t at t = 2.