The Cunninghams are moving across the country. Mr. Cunningham leaves 3.5 hours before Mrs. Cunningham. If he averages 55mph and she averages 65mph, how many hours will it take Mrs. Cunningham

Question

The Cunninghams are moving across the country. Mr. Cunningham leaves 3.5 hours before Mrs. Cunningham. If he averages 55mph and she averages 75mph, how many hours will it take Mrs. Cunningham to catch up to Mr. Cunningham?

Answer 1

3.5 hours head start, going 55mph, when will the wife catch up going 75mph?

(3.5+T)55 = 75T

75T - 55T = (3.5)55

20T = 192.5

T= 192.5/20 = 9.625 = 9 5/8 = 9 hours & 37 minutes and 30 seconds to catch up

in 3.5 + 9.625 = 13.125 hours the guy goes 55x13 1/8 = 721 1/8 miles

in 9.625 hours, his wife goes 75 x 9 5/8 = 721 1/8 miles