Answer
Without compression : 115200000 bits
With compression : 23040000 bits
Work Step by Step
number of bits = sampling rate $\times$ time $\times$ bit depth
=> number of bits = 40000 $\times$ 180 $\times$ 16 = 115200000
---compression ratio = $\frac{uncompressed\space size}{compressed\space size}$
=> $\frac{5}{1}=\frac{115200000}{compressed\space size}$
=> compressed size = 23040000 bits
