Answer:
C1 + C2 = 30 parallel connection
C1 * C2 / (C1 + C2) = 7.2 series connection
C1 * C2 = 7.2 * (C1 + C2) = 216
C2 + 216 / C2 = 30 using first equation
C2^2 + 216 = 30 C2
C2^2 - 30 C2 + 216 = 0
C2 = 12 or 18 solving the quadratic
Then C1 = 18 or 12
Answer:

Explanation:
As we know that the level of intensity is given as

here we know



now the sound is travelling in all possible directions so we have



now for level of sound we have


I think your best bet would be.
It acts in the direction opposite of the motion
The lower layer is thought to be hard and rough