Answer: The amount of Karen's bill = $ 60
Step-by-step explanation:
Given : The expression 10+0.25m can be used to determine the amount o, where m = The number of minutes she talks.
If she talks for 200 minutes in one month, then put m= 200 in the above expression we will get the amount of Karen's bill = 10+0.25(200)
= 10+ 50
= 60
Hence, the amount of Karen's bill = $ 60