Question

On the first day of travel, a driver was going at a speed of 40 mph. The next day, he increased the speed to 60 mph. If he drove 2 more hours on the first day and traveled 20 more miles, find the total distance traveled in the two days.

Answer 1

Answer:

380 miles

Explanation:

Let the time he travelled on the second day = t

Then the first day's time is t + 2

The first day's distance is d+20

The second day's distance is d

The second day's distance is also 60*t or d = 60*t

First day: 40*(t+2) = d + 20

Put the second day's distance into the first day's equation

40(t+ 2) = 60t + 20 Now solve for t. Remove the brackets

40*t + 80 = 60t + 20 Subtract 20 from both sides

40t + 80 - 20 = 60t Combine

40t + 60 = 60t Subtract 40t from both sides

60 = 60t - 40t

60 = 20t Divide by 20

t = 60 / 20

t = 3

Day 2s distance = 60*3 = 180

Day 1s distance = 40*5 =200

Total 380

You may ask where the 20 went. It is a fact relating the distance of day 1 with day 2. No one actually travelled the 20 miles. It is just that there is a difference of 20 miles in the two distances.