Harry drove for 6 hours on the freeway, then decreased his speed by 20 miles per hour and drove for 6 more hours on country road. If his total trip was 624 miles, then what was his speed on freeway?

since distance = speed * time,

6x + 6(x-20) = 624

62

To find Harry's speed on the freeway, we can set up an equation based on the information given.

Let's assume Harry's speed on the freeway was x miles per hour.

So, in the first 6 hours on the freeway, he traveled a distance of 6x miles.

Afterward, he decreased his speed by 20 miles per hour, so his speed on the country road was (x - 20) miles per hour.

In the next 6 hours on the country road, he traveled a distance of 6(x - 20) miles.

According to the given information, his total trip distance was 624 miles.

Therefore, we can write the equation:

6x + 6(x - 20) = 624

Simplifying the equation:

6x + 6x - 120 = 624

12x = 744

Dividing both sides by 12:

x = 62

So, Harry's speed on the freeway was 62 miles per hour.