Question

Train a is traveling at 30 mph faster than train b. If train a travels 350 miles in the same amount of time that train b travels 140 miles how fast is train b traveling

Answer 1

Answer:

20 mph

Step-by-step explanation:

Let speed of Train a = Va mph

Let speed of Train b = Vb mph

Va = Vb + 30

Let time taken for Train a = Ta

Let time taken for Train b = Tb

time taken = distance travelled/speed

Ta = 350/Va = 350/(Vb+30)

Tb = 140/Vb

But they both travel in the same amount of time.

So, Ta = Tb

$\frac{350}{v_{b} + 30}=\frac{140}{v_{b}}$

Cross multiply

$350v_{b} = 140(v_{b} + 30)\\\\350v_{b} = 140v_{b} + 4200\\\\350v_{b} -140v_{b} = 4200\\\\210v_{b} = 4200$

Divide both sides by 210

$\frac{210v_{b} }{210} \frac{4200}{210} \\\\v_{b} = 20 mph$