World Problem Help

Question

One morning, Justin drove 2 hours before stopping to eat lunch at Chick-fil-A. After lunch, he increased his speed by 10 mph. If he completed a 220-mile trip in 6 hours of driving time, how fast did he drive in the morning?

Answer 1

Well, let's take this problem and put it into math terms:

For 2 hours Justin drove Xmph, and then for 4 hours he drove X+10mph for a total of 220 miles.

2x + 4 (x+10)= 220

2x + 4x + 40 = 220

6x + 40 = 220

6x= 180

x= 30mph in the morning