To solve this problem, we will express the conditions as inequalities and then check each of the proposed solutions.
Let \( x \) represent the number of green marbles and \( y \) represent the number of yellow marbles. The two conditions given are:
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The sum of twice the number of green marbles and the number of yellow marbles is more than 20: \[ 2x + y > 20 \]
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The total number of green and yellow marbles is less than 15: \[ x + y < 15 \]
Now let's check each of the proposed solutions:
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(6, 7):
- Check \( 2x + y > 20 \): \[ 2(6) + 7 = 12 + 7 = 19 \quad (\text{not } > 20) \]
- Check \( x + y < 15 \): \[ 6 + 7 = 13 < 15 \quad (\text{true}) \]
- Conclusion: Not a viable solution.
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(10, 5):
- Check \( 2x + y > 20 \): \[ 2(10) + 5 = 20 + 5 = 25 \quad (> 20) \]
- Check \( x + y < 15 \): \[ 10 + 5 = 15 \quad (\text{not } < 15) \]
- Conclusion: Not a viable solution.
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(8, 6):
- Check \( 2x + y > 20 \): \[ 2(8) + 6 = 16 + 6 = 22 \quad (> 20) \]
- Check \( x + y < 15 \): \[ 8 + 6 = 14 < 15 \quad (\text{true}) \]
- Conclusion: Viable solution.
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(3, 12):
- Check \( 2x + y > 20 \): \[ 2(3) + 12 = 6 + 12 = 18 \quad (\text{not } > 20) \]
- Check \( x + y < 15 \): \[ 3 + 12 = 15 \quad (\text{not } < 15) \]
- Conclusion: Not a viable solution.
The only viable solution to the system of inequalities is (8, 6).