Question

Kwesi is putting on sunscreen, and he uses 3 ml to cover 45 cm² of his skin. He wants to know how many milliliters of sunscreen (in g) he needs to cover 240 cm² of his skin, assuming that the relationship between milliliters of sunscreen and the area is proportional.

What is the quantity of sunscreen in milliliters (g) that Kwesi needs to cover 240 cm² of his skin?

Answer 1

Kwesi needs 16 milliliters of sunscreen to cover 240 cm² of his skin. This is found by setting up a proportion and using cross-multiplication to solve for the unknown quantity.

Step-by-step explanation:

To determine how many milliliters of sunscreen Kwesi needs to cover 240 cm² of his skin, we set up a proportion using the information given that 3 ml of sunscreen covers 45 cm² of skin. The relationship is proportional, meaning we can use cross-multiplication to find the unknown quantity.

First, we write the proportion as follows:
(3 ml) / (45 cm²) = (x ml) / (240 cm²)
Next, we cross-multiply and solve for x:
3 ml × 240 cm² = 45 cm² × x ml
720 ml·cm² = 45 cm²·x ml
x = 720 ml·cm² / 45 cm²
x = 16 ml
Thus, Kwesi needs 16 milliliters of sunscreen to cover 240 cm² of his skin.