Shelvin entered a math contest at school. There were 10 problems in the contest. Half of them were worth 3 points if solved correctly and half were worth 5 points if correct. Any problem that was answered incorrectly counted 1 point off.
Each contestant had to answer exactly 5 questions, but they could choose how many of each kind
they wanted to try.
Question:
If Shelvin got 80% of his questions correct and scored 17 points, how many of each kind of question did he get right?
Number of 5-point questions attempted: 3
Number of 5-point questions correct:
Number of 3-point questions attempted: 2
Number of 3-point questions correct:
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Check
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Number of questions attempted: 3 + 2, or 5
Number of questions correct: 3 + 1, or 4
Percentage right: , or 80%
Number of points gained from correct 5-point questions: 3(5), or 15
Number of points gained from correct 3-point questions: 1(3), or 3
Number of points lost from incorrect questions: 1(- 1), or - 1
Total points gained: 15 + 3 - 1, or 17