Correct question is;
Caitlin purchased a prepaid phone card for $20. Long distance calls cost 7 cents a minute using this card. Catin used her card only once to make a long distance all the remaining credit on her card is $16.8. how many minutes did her call last?
Answer:
45 minutes 43 seconds
Explanation:
We are told that she purchase the prepaid phone card for $20.
Now she has $16.8 after making the call.
Therefore;
Amount spent on the call = 20 - 16.8 = $3.2
We are told that the long distance call costs 7 cents per minute. Which is $0.07 per minutes
Thus, time spent = $3.2/$0.07 = 45.714 minutes or 45 minutes 43 seconds