SOLUTION: On Monday Roger drove to work in 45 minutes. On Tuesday he averaged 12 miles per hour more, and it took him 9 minutes less to get to work. How far does he travel to work?

Question 1742: On Monday Roger drove to work in 45 minutes. On Tuesday he averaged 12 miles per hour more, and it took him 9 minutes less to get to work. How far does he travel to work?
Answer by longjonsilver(2297) (Show Source): You can put this solution on YOUR website!
let the speed on Monday be x mph. It takes him 45 minutes (which is 3/4 of an hour), so using speed=distance/time gives:
or . This is equation 1.
On Tuesday, speed is 12mph more, so it is x+12. His time is 9 minutes less, meaning 36 minutes, which is 3/5 of an hour. REMEMBER, the speed is miles per HOUR, so all distances must be miles and all times must be HOURS.
so, its equation is . This is equation 2.
Equation 1 re-arranges to be
Equation 2 re-arranges to be .
We can substitute equation 1 into equation 2 and we get d=36miles.
cheers
Jon.

RELATED QUESTIONS
communiting to work. On Monday, Roger drove to work in 45 minutes. On tuesday he... (answered by ankor@dixie-net.com)

On Monday, Roger drove to work in 45 minutes. On Tuesday he averaged 12 miles per hour... (answered by ankor@dixie-net.com)

On Monday, Roger drove to work in 42 minutes. On Tuesday, he averaged 5 miles per hour... (answered by Paul,wuwei96815)

On Monday, Roger drove to work in 55 minutes. On Tuesday, he averaged 8 miles per hour... (answered by ankor@dixie-net.com)

On Monday, Roger drove to work in 38 minutes. On Tuesday, he averaged 10 miles per hour (answered by ankor@dixie-net.com)

On Monday, Roger drove to work in 2 hours. On Tuesday, he averaged 15 miles per hour... (answered by jsmallt9)

On Monday, Roger drove to work in 2 hours. On Tuesday, he averaged 15 miles per hour... (answered by josmiceli)

On Monday, Roger drove to work in 2 hours. On Tuesday, he averaged 15 miles per hour... (answered by solver91311)

On Monday, Bill drove to work in 50 minutes. On Tuesday, he averaged 12 miles per hour... (answered by stanbon)