Answer
Find out the how many hours has Carlos practiced piano .
To prove
As given


Than

L.C.M of (4,10) = 20



Therefore the total hours Carlos practiced piano is 1.45 hours .
Rebecca payed $35 for the video game, simple math.

Actually Welcome to the Concept of the Symmetry,
Option A.) is correct,
=> N has only the Rotational Symmetry.