How do I calculate the price of 50g of a product, if the total grams of the product cost a certain amount

Question

I am looking for a formula that can calculate cost per 50g. e.g. How do I calculate the price of 50g of Pepper, if 300g costs 132? or How do I calculate the price of 50g of Salt, if 1000g costs 100?

What standard formula could I use?

Answer 1

You have to divide the monetary cost by the given grams, and multiply the result by $50~\text{g}$. Example: $$ \text{Pepper}: \qquad \text{price per 50 g} = \frac{132}{300~\text{g}} \cdot 50~\text{g} \approx 22 $$ If you forget what should be multiplied by what, it's also rather easy to "test out" the numbers. Example: You know that 300 g costs 132. Therefore, one gram costs $132/300= 0.44$, right? Then two grams costs $2\times 0.44 = 0.88$, and 50 grams costs $50 \times 0.44 = 22$. Easy!