Hands-on math!

Washington State Math Olympiad
Hints and Solutions
2014 Grade 7 Algebra
Problem

1) Danny bought a total of 20 game cards. The specialty cards cost $0.25 each and the rest cost $0.15 each. If Danny spent $4.20 to buy these cards how specialty cards did he buy?

2) Tyler drove at a constant speed for 2 hours. He stopped for an hour to do some shopping and have a bite to eat. He then drove back home at a constant speed. Draw a possible graph on the axes provided with time as the input and total distance traveled in the car as the output.)

Problem

3) Before district play, the basketball team won 10 of their games, or 40% of their games. During district play, they won six more games and finished the season having won half their games. What percentage of their games did they win at districts? Round to the nearest percent.

4) I am a mystery number. If you multiply me by 2 and take away 5 the result is the same number when you first add 2 to me and then multiply the result by 5. What number am I?

5) The table shows some data about the number of students enrolled at a junior high. A line fits the data well for the data shown. If the line is accurate, what is an equation you can use to compute the enrollment for 2015 and other years? Use t as the number of years since 2000, and S for student enrollment.