an electronics company assembles two types of tvs: plasma and lcd. a plasma tv costs $400 to assemble and…

an electronics company assembles two types of tvs: plasma and lcd. a plasma tv costs $400 to assemble and takes 40 hours of labor. the lcd tv costs $250 and requires 30 hours of labor. the company has $20 000 in capital, and 2160 hours of labor available for assembly. what is the maximum number of tvs the electronics company can assemble?
Answer
Explanation:
Step1: Define variables
Let $x$ be the number of plasma - TVs and $y$ be the number of LCD - TVs.
Step2: Set up constraints
The cost constraint: $400x + 250y\leq20000$ (capital constraint), which simplifies to $8x + 5y\leq400$. The labor - hour constraint: $30x+40y\leq2160$, which simplifies to $3x + 4y\leq216$. Also, $x\geq0,y\geq0$ (non - negativity constraints).
Step3: Rewrite inequalities for graphing
For $8x + 5y=400$, when $x = 0$, $y = 80$; when $y = 0$, $x = 50$. For $3x + 4y=216$, when $x = 0$, $y = 54$; when $y = 0$, $x = 72$.
Step4: Find the feasible region
The feasible region is bounded by the $x$ - axis, $y$ - axis, $8x + 5y = 400$ and $3x + 4y = 216$.
Step5: Find the corner points of the feasible region
- Intersection of $x = 0$ and $y = 0$: $(0,0)$
- Intersection of $x = 0$ and $3x + 4y=216$: Substitute $x = 0$ into $3x + 4y=216$, we get $y = 54$. So the point is $(0,54)$.
- Intersection of $y = 0$ and $8x + 5y=400$: Substitute $y = 0$ into $8x + 5y=400$, we get $x = 50$. So the point is $(50,0)$.
- Solve the system of equations $\begin{cases}8x + 5y=400\3x + 4y=216\end{cases}$ Multiply the first equation by 4 and the second equation by 5: $\begin{cases}32x+20y = 1600\15x + 20y=1080\end{cases}$ Subtract the second equation from the first: $32x+20y-(15x + 20y)=1600 - 1080$ $32x+20y - 15x-20y=520$ $17x=520$ $x=\frac{520}{17}\approx30.59$ Substitute $x=\frac{520}{17}$ into $8x + 5y=400$: $8\times\frac{520}{17}+5y=400$ $\frac{4160}{17}+5y=400$ $5y=400-\frac{4160}{17}$ $5y=\frac{6800 - 4160}{17}$ $5y=\frac{2640}{17}$ $y=\frac{528}{17}\approx31.06$
Step6: Define the objective function
The objective function is $N=x + y$ (total number of TVs). Evaluate the objective function at the corner points:
- At $(0,0)$: $N=0+0 = 0$
- At $(0,54)$: $N=0 + 54=54$
- At $(50,0)$: $N=50+0 = 50$
- At $(\frac{520}{17},\frac{528}{17})$: $N=\frac{520}{17}+\frac{528}{17}=\frac{1048}{17}\approx61.65$
Since we are dealing with whole number of TVs, we can also test integer points within the feasible region close to the non - integer corner point. By checking integer points, we find that when $x = 30$ and $y = 31$: For the capital constraint: $400\times30+250\times31=12000 + 7750=19750\leq20000$ For the labor - hour constraint: $30\times30+40\times31=900+1240 = 2140\leq2160$ $N=x + y=30 + 31=61$
Answer:
61