One morning, justin drove 2 hours before stopping to eat lunch at pizza hut. after lunch, he increased his speed by 10 mph. if he completed a 330-mile trip in 5 hours of driving time, how fast did he drive in the morning?
Speed can be broken down to distance / time. If we know Justin drive for 2 hours before lunch and his trip was 5 hours total, then we know he drove for 3 hours at the increased speed. 2 hours * the original speed will give us the distance traveled before lunch, and 3 hours * the increased speed will give us the distance traveled after lunch. The sum of these distances is 330 miles.
2x + 3(x + 10) = 330 5x = 300 The original speed was 60 mph.
