Sunny’s Surf Shop sold 160 surfboards this week, which was 320 percent of the number of surfboards sold last week. How many surfboards did Sunny’s Surf Shop sell last week?
320% is a litle more than 300%. And 300% is 3-fold. (3 times)
If 160 is (about) 3 times the number sold last week, then the number sold last week is (about) 1/3 of 160, which is 50- something.
Now one of the answers is dead-on 50.
3 times the number below, 20, is 60. Nowhere near 160, so ignore it.
3 times the number above, 100, is 300. Nowhere near 160, so ignore it.
50 then is the correct choice.
Answer: Option B