Angela's Coins

Angela has 4 coins: a penny, a nickel, a dime, and a quarter. How many different face values can she make using one or more of these coins?

Reading Books

Dr. Hong bought five books for Leo and Angela. During the first week, Leo finished reading four of them, while Angela finished three of them. At least how many books were read by both Leo and Angela?

Dinner Time

It’s dinner time for the Hong family. It takes 30 minutes for Dr. Hong to finish the meal, 30 minutes for Dr. Wang, 80 minutes for Leo, and 60 minutes for Angela. If they start the meal together at 6pm, when will the family finish their meals?

Counting Rectangles

 How many rectangles are in the figure below?

Adding 16 Numbers

Without using a calculator, calculate: 1 + 2 + 8 + 9 + 11 + 12 + 18 + 19 + 21 + 22 + 28 + 29 + 31 + 32 + 38 + 39 = ?