Lona read 40 books for the read-a-thon. She read 30% historical fiction and20% sports stories. The rest were mysteries. How many mysteries did lona read?
20 mysteries. Add 20% and 30% to get 50%. Then rewrite 50% as 50/100. Next multiply 50/100 by 40 to get 2,000/100.The last thing to do is simplify to get 20 and subtract 20 from 40 to get 20 mysteries.
