distance = rate x time
d = rt
rate = distance/time
t = local racer's time
t  3 = Bernard's time
120 105
 = 2( ) Bernard's rate is twice as fast as local racer's rate
t  3 t
120 210
 =  multiplied by 2
t  3 t
120t = 210t  630 crossmultiplied
90t = 630 subtracted 210t
t = 7 divided by 90
t  3 = 4 substituted
local racer's time is 7
Bernard's time is 4
120/(t  3) = Bernard's rate
= 120/4
= 30 is Bernard's rate
105/t = local racer's rate
= 105/7
= 15 is local racer's rate
*McGenius*
