Counting Problem( Week 18 Practice) 1. It takes 6 minutes to cut a piece of wood into 3 pieces. How many minutes will it take to cut the wood into 5 pieces? 2. There are 6 red cards and 9 yellow cards in a box. At least, how many cards do you need to pick out of the box at the same time to make sure that there are two cards with different colors? 3. In a conventional clock with hour, minute, and second hands, how many times does the minute hand pass the hour hand between 10:00 AM and 06:00 PM in a day? 4. In the natural numbers from 1 to 100, how many times does digit '5' show up? 5. A book has 300 pages numbered 1, 2, 3,... and so on. How many times does the digit 8 appear exactly once in the page numbers? |