Question

Bob drove 120 miles on his vacation. He drove an average of 1.2 times faster on the second 60 miles of his trip than he did on the first 60 miles of his trip. Which expression represents the time he spent driving? Let x = his speed on the first half of the trip.

Answer 1

V = x ( his speed on the first half of the trip )
1.2 v = 1.2 x ( his speed on the second half of the trip )
t = d / v
t = 60 / x + 60 / 1.2 x = 60/ x + 50 / x = 110 / x
Answer: A ) 110 / x

Answer 2

Answer:

$\frac{110}{x}$

Step-by-step explanation:

Given,

Total distance = 120 miles,

Here x represents Bob's speed on the first half of the trip( 60 miles ).

$Time=\frac{Distance}{Speed}$

So, the time taken in first half = $\frac{60}{x}$

Now, He drove an average of 1.2 times faster on the second half than first half,

⇒ His speed in second half = 1.2 x,

So, the time taken in second half = $\frac{60}{1.2x}$

Hence, the total time taken by him = the time taken in first half + the time taken in second half

$=\frac{60}{x}+\frac{60}{1.2x}$

$=\frac{72+60}{1.2x}$

$=\frac{132}{1.2x}$

$=\frac{1320}{12x}$

$=\frac{110}{x}$

Which is the required expression.