jack and jill are marathon runners . jack can finish a marathon ( 43 km ) in 4.5 hours and jill can run a marathon in 4.3 hours . what is the ratio of their average running speed ? ( jack : jill )
"average speed of jack = distance / time = 43 / ( 9 / 2 ) = 86 / 9 average speed of jill = 43 / ( 4.2 ) = 10 ratio of average speed of jack to jill = ( 86 / 9 ) / 10 = 86 / 90 = 43 / 45 answer b"
divide(divide(43, 4.5), divide(43, 4.3))