How fast must Horatio ride to finish at the same time as Davie if they are on a scenic tour that is 80 miles long and Davie rides at 20 miles per hour and leaves 90 minutes before Horatio?

Answer 1

You have :
dD = dH = 80 mi VD = 20 mi/h

tH = tD - 90 min = tD - 1.5 h

dD = ( VD ) ( tD )

80 mi = ( 20 mi/h ) ( tD ) ----> tD = 4 h

dH = ( VH ) ( tH ) = ( VH ) ( tD - 1.5 h )

80 mi = ( VH ) ( 4h - 1.5 h ) = ( VH ) ( 2.5 h ) ----> VH = 32 mi/h <-----------------------

Answer 2

Davie travels distance (s) 80 miles in time (t) at velocity (v) of 20 mph.s = vt = 20t = 80; t = 4 hours Horatio leaves 90 minutes (1.5 hours) later so has to get there at same time sohe has (4-1.5) = 2.5 hours to get there. His speed (V) isV = s/t = 80/2.5 = 32 mph

Answer 3

32 miles per hour.