A car starts from one end of a highway and travels towards the other

(1) The bus averaged a speed of 70 miles per hour for the entire journey.

Let the speed of the car = \(x\).

To find how long it will take them to meet, one takes the distance between them, and divides it by their combined speed:

\(\frac{200}{70+x}\)

Without more information, it is impossible to deduce whether the car or the bus travelled further by the time they met.

INSUFFICIENT

(2) They take 1 hour and 20 minutes to meet each other.

One knows that the two vehicles covered 200 miles, in 1 hour and 20 minutes. 1 hour and 20 minutes can be rewritten as \(\frac{4}{3}\) hours​​​​​​​.

With this information, one can solve for their combined speed by using the speed formula Distance/Time

\(\frac{200}{\frac{4}{3}}\)

\(200*\frac{3}{4}\)​​​​​​​

\(150\)

While one knows their combined speed, without knowing more about the respective speeds, or their ratio, one cannot deduce which one drove further when they passed one another.

INSUFFICIENT

(1+2)

Combining the two statements, one knows that the bus travelled at a constant speed of \(70\)mph, that the car travellled at a constant speed of \(x\)mph and that their combined speed was \(150\).

Therefore, \(70+x=150\)

\(x = 80\).

As the car's constant speed was faster than the bus's, the car will have covered a greater distance.

SUFFICIENT


ANSWER C