An accounting-firm employee is asked to shred 900 documents. If he can shred documents at a rate of 7 per minute, the number of documents remaining after1.5 hours of shredding is:
At a rate of 7 documents per minute, the employee can shred 630 documents in 90 minutes. How do you come up with that number? Multiply 7 by 90 (the number of minutes in 1.5 hours). Subtract 630 from 900 total documents to determine that after 1.5 hours of shredding, 270 documents remain.