Hands-on math!

Washington State Math Olympiad
Hints and Solutions
2014 Grade 7 Probability and Statistics
Problem

1) Miguel entered a contest offering prizes to the top 3 finishers. The probability of winning 1st place is 12%, the probability of winning 2nd place is 18%, and the probability of winning 3rd place is 20%. What is the probability that Miguel will not win any prize? Express your answer to the nearest percent.

2) Douglas MS participated in a contest with the results shown. If five teams participated, what is their highest score? (Try and create a data set that works.)

3) An airplane is built to be able to fly on one engine. If the plane's two engines operate independently, and each has a 1% chance of failing in any flight, what is the chance a plane would fail to complete a flight? Express your answer as a percent.

Problem

4) When rolling a single six sided die three times, how much more likely are you to roll all three different numbers compared to all three the same number? Express your answer as a ratio.

5) There are 25 students in Mr. B.'s class. Tori is one of the students who has a $2.00 weekly allowance. Which average, mean or median, should she report to her parents to encourage them to give her a higher allowance? Write your choice and its value.