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A constraint states that x plus 2y must not be more than 20. Is the pair x equal to 6 and y equal to 8 allowed?
AYes, it gives 20
BNo, it gives 22
CYes, it gives 14
DNo, it gives 28
Answer & Solution
Correct answer: B. No, it gives 22
1. A constraint is written as an inequality that any acceptable pair of values must satisfy.
2. Substitute the given values into the left hand side of the inequality.
3. x is 6, so the first term is 6.
4. y is 8, so 2y is 2 times 8, which is 16.
5. Adding the terms gives 6 plus 16, which is 22.
6. The constraint allows no more than 20, and 22 is greater than 20.
7. So the pair lies outside the feasible region and is not allowed.
8. Answering 14 subtracts the two terms instead of adding them.
_Source: Siyavula Mathematics Grade 11 (Everything Maths, CC BY 4.0), Chapter 12: Linear programming_