Problem - Fractional Knapsack

Items have weight and value.

You have capacity W.

You can take fractions of items. Maximize value.

Example: items = [(60,10), (100,20), (120,30)], W = $50$. Format: (value, weight). Ratios: $6$, $5$, $4$. Take all of item $1$ (weight P5, value P6). Take all of item $2$ (weight P8, value P9). Take $2$/$3$ of item $3$ (weight P11, value P12). Total: $240$.