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2017 Math Kangaroo

Problem 8

Problem 8 · 2017 Math Kangaroo Medium
Fractions, Decimals & Percents percent-multiplier

Martina plays chess. This season she has already played 15 games, nine of which she has won. She still has to play 5 more games. How high is her win rate at the end of the season if she wins all remaining games?

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Answer: C — 70 %
Show hints
Hint 1 of 2
First find the final number of wins and the total games played.
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Hint 2 of 2
Win rate is wins divided by total games, as a percent.
Show solution
Approach: add the wins and games, then convert to a percent
  1. If she wins all 5 remaining games she has 9 + 5 = 14 wins.
  2. Total games = 15 + 5 = 20.
  3. Win rate = 14 ÷ 20 = 70%, choice C.
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