Finding optimal blend of items to meet certain criteria Math beginner here. Say I have the following items `Marsbar: sugar 100/lb, salt 5/lb, price $4/lb, inventory: 40lb` `Twix: sugar 100/lb, salt 9/lb, price $7/lb, inventory: 9lb` `Bounty: sugar 105/lb, salt 4/lb, price $3/lb, inventory: 10lb` and I need to make a `3 lb` blend of these items to the lowest price, where the minimum criteria for the blend is: `sugar: 101/lb, salt: 6/lb` Does anyone know how to solve this or can maybe give me a hint, and potentially with more properties than sugar and salt?

Words to equations: $$\begin{cases}100m+100t+105b\geq 101\times 3\\\5m+9t+4b\geq 6\times 3\\\m+t+b=3\end{cases}$$ where $m$ is the pounds of Marsbars, $t$ for Twix, and $b$ for Bounty. We want to minimize $P=4m+7t+3b$, where $P$ is the total price. The above system yields $b\geq\frac{3}{5}$ and $t\geq\frac{9}{10}$ and $m\geq\frac{3}{2}$ by simple rearranging and substitution. Hence, the minimum solution occurs at $(m,t,b)=\left(\frac{3}{2},\frac{9}{10},\frac{3}{5}\right)$ with a price of $\$14.10$.