Question

Lu can type 140 words in 5 minutes, and Ray can type 140 words in 4 minutes. How many more words can Ray type than Lu in 10 minutes?

Answer 1

70

Explanation:

If Lu can type 140 words in 5 minutes, that means she can type approximately 28 words per minute. (140/5). Ray can type 140 words in 4 minutes, approximately 35 words per minute (140/4).
The question, however, is asking for 10 minutes. So, you would multiply these values by 10. 28x10=280. 35x10=350. Now, subtract. 350-280=70. So, he can type 70 more words.