Question

Candice leaves on a long trip driving at a steady rate of 25 miles per hour. Her sister Liz leaves from the same location traveling to the same destination 4 hours later. She drives at a steady rate of 50 miles per hour. How long after Liz leaves home will she catch up to Candice?

Answer 1

Answer: 3 hours

Look below

0

25

50

75

100 (other sister starts) 50

125. 100

150. 150

Answer 2

After 4 hours Liz will catch up to Candice.

Explanation:

Let Liz will catch up Candice after t hours.

Liz is driving with a speed of 50 miles per hour.

So distance covered by Liz in t hours = Speed × Time

= 50t miles

Time taken by Candice to cover the same distance will be = (t + 4) hours

(Candice has started 4 hours before her sister Liz)

Since Candice is driving with a speed of 25 miles per hour so distance covered in (t + 4) hours = 25(t + 4) miles

Distances covered by Candice and her sister Liz will be same when Liz Catches up Candice.

Therefore, 50t = 25(t + 4)

50t = 25t + 100

50t - 25t = 100

25t = 100

t =
`(100)/(25)=4` hours

After 4 hours Liz will catch up Candice.