In this question, the wording has to be noted very carefully. It is given that the time for practicing each of the 3 piano solos is 5/12 hour. So from this wording we understand that there are three solos and each solo takes 5/12 hours of practice by Richard. Now let us come down to the solving part.
So
For practicing 1 piano solo, Richard takes = 5/12 hours
Then
For practicing 3 piano solos the amount of time taken by Richard = (5/12) * 3
= 5/4 hours
= 1 1/4 hours
So the total practice time required by Richard is 1 1/4 hours.