Distance Question Help

[TheBlueStar]

Hey all!

I have been prepping today for an upcoming exam in my math course and there is one question on the practice exam I get wrong each time and I just can't figure out how to solve it. I've tried googling to see if I could figure out the equation of how to solve with no luck, hopefully someone here can help show me how to solve this type of problem.

"Chelsea currently walks to school from her apartment, which is 1.3 miles away from her first class. She typically walks at a speed of 3 miles per hour. She is considering buying a used bicycle from Deseret Industries so she could ride to campus. She figures that if she were riding a bike, she could go about 6 miles per hour. How many minutes could she save in getting to class each morning if she were to ride the bike?"

Thanks for any help!

Zach

 

[mmm4444bot]

Do you remember the relationship between distance travelled (D), rate of travel (R), and elapsed time (T)? In your class, rate means speed.

D = R ∙ T

This formula calculates the distance, if you know the rate and the time.

The equation can be solved for R or T, by division.

R = D/T

This formula calculates the rate, if you know the distance and the time.

T = D/R

This formula calculates the time, if you know the distance and the rate.

You can use the given information to calculate the two times, and then use subtraction to find their difference.

The difference will be in hours (since the rates are given in miles per hours). Convert your answer to minutes.

If you would like more help, please show us how far you got or explain any uncertainty. ?
[imath]\;[/imath]

 

[Denis]

Chelsea currently walks to school from her apartment, which is 1.3 miles away from her first class. She typically walks at a speed of 3 miles per hour. She is considering buying a used bicycle from Deseret Industries so she could ride to campus. She figures that if she were riding a bike, she could go about 6 miles per hour. How many minutes could she save in getting to class each morning if she were to ride the bike?"

Your problem simplified (teacher that wrote that should be fired!):
Chelsea walks 1.3 miles to school, at a speed of 3 miles per hour.
If she uses her bicycle instead, her speed is 6 miles per hour.
How many minutes does she save when using her bicycle?

Can you tell us where you're stuck ?
Are you using formula: speed = distance / time ?

 

[Deleted member 4993]

Thanks for the forums))) My son asked me to help him with his homework, but I myself don’t remember anything from the curriculum, your post helped me.

Also think about:

If you double the speed (3 mph to 6mph, covering the same distance) - what will happen to time elapsed?

 

[Deleted member 4993]

"Chelsea currently walks to school from her apartment, which is 1.3 miles away from her first class. She typically walks at a speed of 3 miles per hour. She is considering buying a used bicycle from Deseret Industries so she could ride to campus. She figures that if she were riding a bike, she could go about 6 miles per hour. How many minutes could she save in getting to class each morning if she were to ride the bike?"

So the alternate way to attack the problem:

Time taken by Chelsea to walk to school = D/R = 1.3/3 hours

Riding the bike will double the speed. So

Time taken by Chelsea to ride to school = D/R = 1.3/6 hours

Time saved by riding = 1/2 * 1.3/3 hours = 60 * 1/2 * 1.3/3 minutes = 10 * 1.3 minutes = 13 minutes