Question

3. Jackson drove a car from Amherst to Boston at the

constant speed of 60 miles per hour. On the way back
along the same route, he drives at a constant speed of
40 miles per hour. If he took 6 hours for the entire
trip, what is the distance, in miles, from Amherst to
Boston?
A) 120
B) 144
C) 160
D) 240

Answer 1

Answer: Let's denote the distance from Amherst to Boston as "d" (in miles).

When Jackson drove from Amherst to Boston at a constant speed of 60 miles per hour, the time taken for this leg of the trip can be calculated using the formula: time = distance / speed.

So, the time taken from Amherst to Boston is:

t1 = d / 60

On the way back, Jackson drove at a constant speed of 40 miles per hour. Similarly, the time taken for this leg of the trip is:

t2 = d / 40

The total time for the entire trip is given as 6 hours:

t1 + t2 = 6

Substituting the expressions for t1 and t2:

d / 60 + d / 40 = 6

To solve this equation, we can find a common denominator:

(2d + 3d) / (2 * 60) = 6

5d / 120 = 6

Cross-multiplying:

5d = 6 * 120

5d = 720

Dividing both sides by 5:

d = 720 / 5

d = 144

Therefore, the distance from Amherst to Boston is 144 miles.

The answer is B) 144.