Richa S. answered • 07/20/20

Experienced Tutor, Specialized in Biology and English

We will take formula D = RT

As the passenger train is 12mph faster than freight train, so for passenger train

D =RT

280 = (R +12)T

T = 280 / R + 12

For Freight train

220 = RT

T = 220/ R

As time taken by both trains is same, so

280 / R + 12 = 220/ R (we will cross multiply)

280 R =220R + 2640

280 R - 220R = 2640

60 R = 2640

R = 2640/60

R = 44mph (for freight train)

As the passenger train is 12mph faster than freight train, so value of R for passenger train will be 44 + 12 = 56mph.

you can also check your answer by putting these values in formula T = D/R as time is same for both trains

T(P) = T(F)

D/R = D/R

280/56 = 220/44

5 = 5