1999 MIDDLE SCHOOL MATH OLYMPIAD
SIXTH GRADE PROBABILITY & STATISTICS
(Make sure you include the units in your answer!)
1. I have a bag of marbles containing the following: 8 red marbles, 16 blue marbles, 4 green marbles, 7 yellow marbles. What is the probability of drawing a marble that is not yellow? Express your answer as a fraction in lowest terms.
2. The scores on Tabitha's 3 previous math quizzes were 86, 88 and 90. If she needs an average of 90 or more to get an "A", what is the lowest score she needs on her 4th test to get an A in math?
3. What is the value of X that will make the mean, median, and mode of this set of numbers all the same?
8, 5, 2, 8, 5, 2, X
4. A sandwich shop has 3 meats: ham, turkey and roast beef. They have 2 kinds of bread: white and whole wheat. They have 4 choices of vegetable: lettuce, onions, tomato, pickle. They have 4 choices of dressing: Italian, Thousand Island, Mustard, Ketchup. If you select 1 meat, 1 bread, 2 different vegetables and 1 dressing, how many different sandwiches could the shop make?
5. In a video game, the player must fight a scaly monster in room 1, a Ninja warrior in room 2, and a giant snake in room 3. If the player gets through all 3 rooms, she has won! If 10 people play this video game, 8 get past the scaly monster. The Ninja warrior is twice as difficult as the scaly monster, and the giant snake is twice as difficult as the Ninja warrior. What is the average player's probability of winning this video game? State your answer as an exact percent.