Formulating linear programs Quiz

1. Which constraint needs a surplus variable?

• A. $2x+y\le9$
• B. $x+3y\ge6$
• C. $x+y=4$
• D. $x\ge0$

2. For $5x+2y\le40$ with $x=4$ and $y=6$, what is the slack variable $s$?

• A. $4$
• B. $6$
• C. $8$
• D. $12$

3. In $x+y-s+t=7$, what does $t$ represent?

• A. Unused resource
• B. Excess over the minimum
• C. Profit
• D. A device to give a starting basic feasible solution

4. Which statement about slack and surplus variables is correct?

• A. Both must be non-negative
• B. A slack variable is subtracted
• C. A surplus variable is added
• D. A surplus variable belongs to a $\le$ constraint

5. A company maximises profit $P=4x+7y$. The objective row is written as

• A. $P+4x+7y=0$
• B. $P-4x+7y=0$
• C. $P-4x-7y=0$
• D. $4x+7y-P=1$