Question

The Indianapolis 500 is one of the most exciting events in sports. Each spring, 33 drivers compete in the 500-mile race, sometimes hitting speeds of more than 220 miles an hour. The general formula for computing distance is rate (or speed) multiplied by time, given a steady average speed. The formula may be written d = rt. Answer today's project questions on speed, distance, and time.

The driver's average speed to complete all 8 laps is ______ miles per hour. Round to the nearest tenth of a mile per hour.

Answer 1

1. d = r*t

if the race is 8 laps and the total miles is 500, that means that each lap represents 62.5 miles.
if the driver does the first 3 laps at 185 miles per hour, we use d = r*t.
we have the equation:

3*d/(185)

next part

5*d/(200)
add together

3d/185 + 5d/200 = t

2. we need to use percentages.

the percent the driver drove 185 miles per hour is 3/8.
the percent the driver drove 200 miles per hour is 5/8

185*(3/8) + 200*(5/8) = 69.375 + 125 = 194.375 mph
nearest tenth : 194.4

hope this help