Cindy
60 x 60 = 3600 (Amount of words typed per hour)
3600 x 3 = 10800 (Amount of words typed for 3 hours)
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Bob
20 x 60 = 1200 (Amount of words typed per hour)
10800 รท 1200 = 9 (Number of hours needed to finish the essay)
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So your answer is 9
Hope this helped. Have a great day!