math prob

[elz787]

Two automobiles A and B, leave at the same time and travel the same route. Automobile A goes at a rate of 55 miles per hour. Automobile B travels at a rate of 40 miles per hour . How many hours after theybegin their trip will automobile A be 60 miles ahead of automobile B? Answer is 4 hours.

How did you work this problem ? mucho thanks!

 

[Comet208]

D = V.T

Distance = velocity X Time

Da = Db => Va x Ta = Vb x Tb

55 Ta = 40 Ta + 60

15 T = 60

T= 4

 

[SunnyD0119]

i just did this
55-40=15
60\14=4

 

[jhui]

you could always just do trial and error if u dont want to remember so many formulas. its only 5 choices u try anyways, doesnt take too long.

 

[elz787]

thanks guys.

 

[BenignDMD]

55x = 40x+60
x=4