Final answer:
Javier sold a total of 7/10 of his coin collection by selling half of it one day and another 1/5 on another day. We found this by converting the fractions to have the same denominator and then adding them.
Step-by-step explanation:
The student is asking how much of Javier's coin collection he sold after selling half of it on one day and then another 1/5 of the collection on another day. To find the total fraction of the collection sold, we should add the fractions together.
First, Javier sells 1/2 (or 0.5) of his collection.
On another day, he sells 1/5 of his collection. To add these fractions, they must have a common denominator. Since the denominator 10 is common for both 2 and 5, we convert 1/2 to 5/10 and 1/5 to 2/10.
Now, we can easily add these fractions: 5/10 (1/2) + 2/10 (1/5) = 7/10.
This means Javier has sold a total of 7/10 of his coin collection over the two days.