Answer :
Should be within 45 minutes.
Work:
Mary:
rate = 7 mph ; time = t hrs. ; distance = 7t miles
Janet:
rate = 5 mph ; time = t hrs. ; distance = 5t miles
Should be within 45 minutes.
Work:
Mary:
rate = 7 mph ; time = t hrs. ; distance = 7t miles
Janet:
rate = 5 mph ; time = t hrs. ; distance = 5t miles