Could you explain how to do this sum please?

Dear student,

given, pitch same,
amplitude is in ratio 1:3
we know loudness is proportional to square of amplitude. 
$$\begin{gathered} i. loudness ratio of the two waves={( \frac{1}{3})}^2 =\frac{1}{9} \\ hence the ratio of laoundenss =1:9 \\ ii. pitch is directly proportional to frequency \\ so as pitch is same, frequency of two waves will be same. \\ so ratio of frequency = 1:1 \end{gathered}$$
Regards,