Ruth was hauling a wide load out of Boston At 400 am she hea

Ruth was hauling a wide load out of Boston. At 4:00 a.m. she headed south from exit 129 at an average of 25 mph. Nadia headed south from the same exit at 11:00 a.m. in her Toyota. By 5:00 p.m. the same day Nadia was 17 miles ahead of Ruth. what was Nadia\'s average speed?
Okay, so I have NO idea how to do this. what times do I use? My teacher has my class use the whole D=RT formula, but since there are two people and one is ahead of the other how do I work this out?
Please and thank you

Solution

Make this chart. D R T Ruth Nadia We want to know Nadia\'s speed, so we put x for Nadia\'s rate (speed): D R T Ruth Nadia x >>...Ruth...headed south...at an average of 25 mph. So we put 25 for Ruth\'s speed D R T Ruth 25 Nadia x Ruth traveled from 4 AM to 5 PM, which is 13 hours. So we put 13 for Ruth\'s time D R T Ruth 25 13 Nadia x Now we use D=RT to get Ruth\'s total distance at 5PM. D = (25)(13) = 325 miles, so we put 325 for Ruth\'s distance D R T Ruth 325 25 11 Nadia x Nadia traveled from 11 AM to 5 PM, so her time was 6 hours. So we put 6 for Nadia\'s time. D R T Ruth 325 25 11 Nadia x 6 Now we use D=RT to get Nadia\'s total distance at 5PM. D = (x)(6) = 6x miles, so we put 6x for Nadia\'s distance D R T Ruth 325 25 11 Nadia 6x x 6 Now that the chart is complete, we make the equation from what we didn\'t use to make the chart. That was this: >>...By 5:00 p.m. the same day Nadia was 17 miles ahead of Ruth...<< So Nadia\'s distance = Ruth\'s distance + 17, so 6x = 325 + 17 6x = 342 Divide both sides by 6 x = 57 mph