Question

Mark and Sandy are participating in a Bike-a-Thon for charity. Mark oversleeps, so Sandy gets a one hour head start and bikes at a speed of 12 miles per hour. To catch up to Sandy, Mark decides that he needs to bike at a speed of 15 miles per hour.

1. Make a chart that shows how far Mark and SAndy ride their bikes during the first three hours of the Bike a thon
Hour 1: Mark 15mph Sandy 12mph
Hour 2: Mark 30mph Sandy 24mph
Hour 3: Mark 45mph Sandy 36mph

Answer 1

You missed the fact that Sandy had a one hour head start.

At the end of:
Hour 1: Sandy -- 12 m; Mark 0
Hour 2: Sandy -- 24 m; Mark 15
Hour 3: Sandy -- 26 m; Mark 30

Answer 2

Thank you.

2. WRite an expression that represents Sandy's journey. Be sure to define your variables

t=hour
12t + 12

Answer 3

You're welcome.

12t

Answer 4

But didn't she have a one hour head start so she would have had an extra 12 m?

Answer 5

You just need an expression that represents her journey. It doesn't make any difference what time she started.