Answer:
The speed Alex was going first was 16 mph
Step-by-step explanation:
The distance Alex was walking = 48 mile
The speed with which Alex was walking for the first half of the time = 2 × The speed Alex was walking for the second half of the time
The total time Alex spends on the road = 4 hours
Let x represent the speed with which Alex was walking in miles per hour, (mph), the first half of the time
Therefore, we have;
x × 2 + x/2 × 2 = 48
3·x = 48
∴ x = 48/3 = 16
Therefore, the speed with which Alex was walking in miles per hour, (mph), the first half of the time = x = 16 mph
Alex was going at 16 miles per hour (mph) first.
