Answer: his speed when skateboarding is 6 mph and when walking is 3 mph
Step-by-step explanation:
Let x represent Marlon's walking speed.
Marlins speed on his skateboard is 2 times his walking speed. This means that his skating speed would be 2x.
At 1:30 Marlon left his house to go to the beach a distance of 6.75 mi. He rode his skateboard until 2:15. This means that the total time he spent skating is 45 minutes = 45/60 = 0.75 hours
Distance = speed × time
Distance covered while skating would be
2x × 0.75 = 1.5x
He walked the rest of the way. He arrived at the beach at 3:00. This means that the time that he spent walking is 45 minutes = 0.75 hours.
Distance covered while walking would be
x × 0.75 = 0.75x
Total distance covered is 6.75 miles. Therefore
1.5x + 0.75x = 6.75
2.25x = 6.75
x = 6.75/2.25
x = 3 miles per hour
His skating speed = 2 × 3 = 6 miles per hour.
