Food A ( $x$ kg) gives 2 units of protein and 3 units of iron per kg; food B ( $y$ kg) gives 4 units of protein and 1 unit of iron per kg. A meal needs at least 20 units of protein and 12 of iron. Which constraints are right?

2x + 4y \ge 20,\ 3x + y \ge 12

Correct answerYour answer

2x + 3y \ge 20,\ 4x + y \ge 12

Correct answerYour answer

2x + 4y \le 20,\ 3x + y \le 12

Correct answerYour answer

4x + 2y \ge 20,\ x + 3y \ge 12

Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer A

Correct answer: A

Write each resource as (amount used per unit) × (number of units), added over the products.
'At most' or 'available' gives ≤, 'at least' or 'must give' gives ≥; a profit is maximised and a cost minimised.

Ten questions from Linear Programming, at your own pace.

Food A (xxx kg) gives 2 units of protein and 3 units of iron per kg; food B (yyy kg) gives 4 units of protein and 1 unit of iron per kg. A meal needs at least 20 units of protein and 12 of iron. Which constraints are right?