Math Olympiad 4( Week 41 Quiz 8) 1. Helen want to make a ring for graduation. She can choose from 5 types of stones and 6 types of metals. How many combinations of a stone and a metal are there? 2. Using digits 1, 2, 3, 4, 5, 6, 7, 8, and 9 (Each digit can be used as many times as you want), how many 2-digit numbers can you make? 3. The sum of two numbers is 486. The larger number is 36 more than 5 times the smaller number. What is the bigger number? 5. Richard spent $1440 for a vacation, which was 10% of his savings. How much was in his savings (in dollars) before the spending? 7. The cost of 8 science books plus 5 history books is $7.00 more than the cost of 9 science books plus 4 history books. A history book costs $20.01. What is the cost of a science book? 8. 16 people form a chess club and arrange for each person to play each other exactly a match. How many matches in total will be played? 9. The length of a rectangle is 5 times its width. If its perimeter is 780 inches, what is the length (in inches)? 12. Susan has 4 blouses and 7 pairs of pants. How many different outfits can she make from these clothes? 13. Eric stopped at a restaurant for dinner. There are 19 kinds of main dishes and 8 kinds of soup. How many possible combinations can be made from the menu (Each with one main dish and one soup)? 14. Three students shared a computer for their science project for a total of 3 hours. At any specific time, only one student was allowed to use the computer. The first student used 25% of the total time, and the second student used the computer 30% of the total time. The rest was used by the third student. For how many minutes did the third student use the computer? 15. The tickets for a concert cost $30 each. However, children can get a 10% discount. A group of 12 people consisting of children and adults paid a total of $342 for the concert. How many children were there in the group? |