Answer:
Yes, his collection will be complete by the time his grandfather visits
Explanation:
Here, we want to know if his collection would be complete by the time his grandfather visits.
From the question;
he has collected 13 different quarters in 2.25 months
At the same rate, x different quarters will be collected in 9 months
Thus, mathematically;
x * 2.25 = 13 * 9
x = (13 * 9)/2.25 = 52
Thus, at this rate he would have collected 52 quarters in 9 months.
Since he has only 50 to collect, it means his collection would be complete by the time his grandfather visits