Explanation needed tip by using chain rule

1/(810pi) cm/s

Step-by-step explanation:

V = pi×r²×h = pi×90²×h = 8100pi×h

dh/dt = dh/dV × dV/dt

dV/dh = 8100pi

dV/dt = 10

dh/dt = (1/8100pi) × 10

= 1/(810pi) cm/s

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads