John can read a book 60% faster than his brother.  If his brother takes 8 hours to read a book, how long would it take John to read 3 books?
Reading 60% faster means John's brother takes 1+.6=1.6 times as long as John to read
So John reads a book in 8/1.6=<<8/1.6=5>>5 hours
So it would take John 5*3=<<5*3=15>>15 hours to read 3 books
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