Let Noah's rate = R ..... then Grady's rate is R + .60R
And Rate * Time = Distance ...so....
R(2) + 12 = [R + .60R](2) .... simplify
2R + 12 = 2R + 1.2R subtract 2R from each side
12 = !.2R divide both sides by 1.2
R = 10 mph ......and this is Noah's rate
Note that Grady's rate = 10 + .60(10) = 16 mph
And, as Anonymous has pointed out, Grady rides 32 miles and Noah rides 20 miles
