# Problems of the Week with Answers!

Jun 22, 2017 | Stone Oak

Lower Elementary:
Question:  Start with 1. Add 15. Subtract 11. Double it. Add 1. Multiply by 5. Subtract 30. Take away half. What’s the new number?
Solution:  After we add 15 to 1, we have 16. Then we subtract 11, so we have 16 – 11 = 5. After we double it, we have 5 × 2 = 10. One more makes 11. Next, we have 11 × 5, which makes 55. Thirty less than 55 is 25. Since 25 is odd, we can find half of it by finding half of 24 and half of 1. Half of 24 is 12, and half of 1 is ½, so that gives us a final answer of 12½.

Upper Elementary:
Question:  It takes Evelyn 8 minutes to jog all the way around a circular path. If Evelyn starts at 6:35 am and jogs around the path exactly 8 times, what time will it be when she’s done?
Solution:  Eight minutes, 8 times is 8 × 8 = 64 minutes. There are 60 minutes in an hour, so Evelyn jogs for 1 hour and 4 minutes because 64 minutes – 60 minutes (1 hour) = 4 minutes. One hour after 6:35 am is 7:35 am, and 4 minutes after that is 7:39 am.

Middle School:
Question:  24–karat gold is 100% pure gold. How many ounces of pure gold are there in a 15 pound, 16–karat gold bar?