Answer:
x = 4.363636...
Step-by-step explanation:
Set up a ratio
6 miles : 55 minutes
x miles : 40 minutes
Cross Multiply
55x = 40*6
55x = 240
55x / 55 = 240 / 55
x = 4.363636...
400 - 3x = 163
Add 3x to both sides.
400 = 163 + 3x
Subtract 163 to both sides.
237 = 3x
237/3 = 79
Your answer is option C. Hope I answered it on time