SOLUTION: Mary can jog, on average, 2 miles per hour faster than her husband, James. James can jog 6.6 miles in the same amount of time it takes mary to jog 9 miles. Mary can jog____ miles p

Algebra ->  Real-numbers -> SOLUTION: Mary can jog, on average, 2 miles per hour faster than her husband, James. James can jog 6.6 miles in the same amount of time it takes mary to jog 9 miles. Mary can jog____ miles p      Log On


   



Question 950350: Mary can jog, on average, 2 miles per hour faster than her husband, James. James can jog 6.6 miles in the same amount of time it takes mary to jog 9 miles. Mary can jog____ miles per hour?
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
J=Jame's rate; M=Mary's rate=J+2mph
6.6 mi/J=9 mi/M Substitute for M
6.6 mi/J=9 mi/J+2 Multiply each side by (J)(J+2) (cancel both denominators)
6.6 mi(J+2mph)=9 mi(J)
6.6J+13.2=9J Subtract 6.6J from each side.
13.2=2.4J Divide each side by 2.4
5.5mph=J James jogs 5.5 mph.
M=J+2mph=5.5mph+2mph=7.5 mph ANSWER: Mary jogs 7.5 mph.
CHECK
James jogs 6.6 mi while Mary jogs 9 mi
6.6 mi/J=9 mi/M
6.6 mi/5.5 mph=9 mi/7.5
1.2 hrs=1.2 hrs