Final answer:
To find out how many words can be typed in 18 minutes, divide the words typed by the time taken and multiply by 18. The answer is A)720 words.
Step-by-step explanation:
To find out how many words can be typed in 18 minutes, we need to determine the typing speed per minute. We can do this by dividing the number of words typed by the number of minutes it took. So, the typing speed per minute is 480/12 = 40 words per minute. Now, we can multiply the typing speed per minute by the number of minutes (18) to find out how many words can be typed in 18 minutes. 40 x 18 = 720 words. Therefore, the answer is option A) 720 words.