Answer:
1. 5 miles/hour
2. 12 apples
Explanation:
1. Mary drove 55 miles in 11 hours.
To find the unit rate of her speed we will use the formula
Speed =

=

= 5 miles/hour
The unit rate of Mary's speed would be 5 miles per hour.
2. The ratio of apples to oranges = 3 : 15 =

=

Let the total number of apples be x.
Therefore,
=

By multiplying with 60 on both the sides.
x =

x = 12
The number of apples are 12.