Final answer:
To find the length of the whole trip, you can set up a proportion using the given information. The family has completed 70% of the trip, which corresponds to traveling 35 miles. By solving the proportion, the whole trip is 50 miles long.
Step-by-step explanation:
To find the length of the whole trip, we can set up a proportion using the given information. The family has completed 70% of the trip, which corresponds to traveling 35 miles. Let x represent the total length of the trip. We can set up the proportion:
(70/100) = 35/x
To solve for x, we can cross multiply and divide:
70x = 35 * 100
x = 3500 / 70
x = 50
Therefore, the whole trip is 50 miles long.