Question

An object is traveling at a steady speed of 8 2/3 miles per hour. How long will it take the object to travel to 5 1/5 miles If the object reduces its speed by `\frac{1}{2}`, what is its speed? If the object reduces its speed by 30%, what is its speed after the reduction?

Answer 1

3/5 hour

4 1/3 miles per hour

6 1/15 miles per hour

Explanation:

Given that the object is travelling at a steady speed of 8 2/3 miles per hour and covers 5 1/5 miles

Recall that distance = speed * time

hence

5 1/5 miles = 8 2/3 miles per hour * time t

26/5 = 26/3 * t

Multiply both sides by 3/26

26/5 * 3/26 = t

t = 3/5 hour

If the object reduces its speed by 1/2, the new speed

= 1/2 * 8 2/3 miles per hour

= 1/2 * 26/3

= 13/3 miles per hour

= 4 1/3 miles per hour

If the object reduces its speed by 30%, the new speed

= 8 2/3 miles per hour - 30% * 8 2/3 miles per hour

= 0.7 * 8 2/3 miles per hour

= 7/10 * 26/3

= 91/15

= 6 1/15 miles per hour