Question

Driving across country, mike drove for 3 hours at a certain rate and for 4 hours at a rate 10 mph faster. If his total distance covered was 495 miles, then what was his slower rate?

Answer 1

Answer:

65 mph

Step-by-step explanation:

Let x mph be Mike's slower rate, then his faster rate is x+10 mph.

1. Mike drove for 3 hours at a slower rate, thus he drove

$x\cdot 3=3x\ miles$

2. Mike drove for 4 hours ar a faster rate, so he drove

$(x+10)\cdot 4=4x+40\ miles$

3. In total he drove 495 miles. Hence

$3x+4x+40=495\\ \\7x=495-40\\ \\7x=455\\ \\x=65\ mph$