Question

Car A and car B are traveling at different speeds. Car A can travel 175 miles in the same time it takes car B to travel 125 miles. If car A travels 20 mph faster than car B, how fast (in mph) is car B traveling? (Enter an exact number.)

Answer 1

The speed of car B is 50 mile per hour

Explanation:

Given as :

The Distance travel by car A = 175 miles

The Distance travel by car B = 125 miles

The Time taken by both car A and B is same = T hours

Let The speed of car B = S mile per hour

So, The speed of car A = ( S + 20 ) mile per hour

Now, Time =
`(Distance)/(Speed)`

So , For Car A ,

T =
`(175)/((S + 20 ))`

For Car B ,

T =
`(125)/((S)`

So,
`(175)/((S + 20 ))` =
`(125)/((S)`

Or, 175 × S = 125 × ( S + 20 )

Or, 175 S - 125 S = 125 × 20

Or, 50 S = 2500

∴ S =
`(2500)/((50)`

I.e S = 50 mph

And S + 20 = 50 + 20 = 70 mph

The speed of car A = 70 mph

The speed of car B = 50 mph

Hence The speed of car B is 50 mile per hour Answer