On the package of cookies Martino reads that the energy value of 100 grams of the product is 400 kcal; moreover, a single cookie, whose weight is 25 grams, contributes 5 percent to the individual daily energy intake. It helps Martino to estimate that energy requirement based on the information listed on the package. How many cookies would be enough to cover that requirement?
Edit my attempt after the comment of @Gerry Myerson:
If the energy value of $100$ grams of cookies is $400$ kcal and a single cookie weighs $25$ grams, we can calculate the energy intake of a single cookie as follows:
$$\text{Energy intake per cookie} = \frac{25}{100} \times 400 \, \text{kcal} = 100 \, \text{kcal}$$
Now, since the individual cookie contributes $5\%$ to the individual daily energy requirement, we can estimate the daily requirement as follows:
$$\text{Individual daily requirement} = \frac{\text{Energy intake per biscuit}}{0.05} = \frac{100}{0.05} = 2000 \, \text{kcal}$$
Thus, according to the information on the package, Martino would have an estimated daily energy requirement of $2000$ kcal. Each cookie contributes $100$ kcal, so the number of cookies needed per day to cover this requirement would be:
$$\text{Number of cookies needed} = \frac{\text{Individual daily requirement}}{\text{Energy intake per cookie}} = \frac{2000}{100} = 20 $$
Is there another way to solve the question?
