Distance<-------------300--------------><-------------------x-----------------> ⊕---------------------------------⊕--------------------------------------⊕ Express Freight Overtaking point Speed 55 speed 30
Let x be the distance travelled by Freight until the point of overtaking Time = Distance/Speed, then:
Time (freight) = Distance (fright)/Speed (freight) And Time (Express) = Distance (Express)/Speed (Express). Now plug in the relative number:
Time (freight) = x/30 and Time (express) = (x+300)/55. But note that both times are equal, then: x/30 = (x+300)/55 OR (x÷30 = (x+300)÷55) [Answer C] Now let's find the distance x. Cross multiplication;
55x= 30(300+x) →55x = 9,000 + 30x 55x - 30x = 9,000 → 25x = 9,000 and x = 9,000/25 = 360 miles Time needed for Freight to travel 360 m = 360/30= 12 Hours Time needed for Express to travel (300+360) m = 660/55= 12 Hours As you see, it's the same time of 12 hours Don't forget that Distance = Speed x time or time = Distance/Speed, etc.
