You driving to a meeting at 60 miles per hour. At 50 miles from your destination you realize you will be 5 minutes late unless you speed up. To arrive on time, how many miles per hour must you increase your speed?You driving to a meeting at 60 miles per hour. At 50 miles from your destination you realize you will be 5 minutes late unless you speed up. To arrive on time, how many miles per hour

must you increase your speed?

Solve the problem using the approach used in the examples above. Then use an alternative approach to check the solution. No need to use the IPO worksheet

General equations:
d1= r1 * ti
d2 = r2* t2


Check: Work the problem using times in minutes and rates in miles per minute.
Traveling at 60 mph you are going a mile a minute
Thus it will take 50 minutes to go 50 miles
At the faster speed the trip will be 5 minutes less:
/2= 50 — 5 = 45 minutes
Rate needed to travel 50 miles in 45 minutes is:
50 = r2 * 45
r2 50 / 45 miles per minute
Express rate in miles per hour
r2 = (50 / 45) (miles / min) * 60 (nom / hour)
r2 = (60 * 50 / 45) (miles / hour)
r2 = 66 and 2/3 mph
Find the rate increase form 60 mph
Increase = 66 and 2/3 less 60
Increase = 6 and 2/3 mph
The solution checks.