Answer:
Kwesi needs 16 ml or 16 g of sunscreen to cover 240 cm² of his skin.
Explanation:
It is given that Kwesi is putting on sunscreen. He uses 3 ml to cover 45 cm² of his skin.
Let Kwesi needs x ml of sunscreen to cover 240 cm² of his skin.
It is given that relationship between milliliters of sunscreen and area is proportional.
![(3)/(45)=(x)/(240)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ph4cp0z504tpdk2ynsxfl09ko0shtavxss.png)
![3* 240=45* x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/h165ij6i2w0l2ayelcrbif8cblpeming0v.png)
![720=45x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/g88i2bry27gwv6zchhxx6g13sbdpr0wqzh.png)
Divide both sides 45.
![16=x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/pusa725v6pq9sw4af2oix32zatloyo03ka.png)
We know that
![1\text{ ml}=1g](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ngefvng9czl8z7vmmfysazwq8bw705mquu.png)
Therefore Kwesi needs 16 ml or 16 g of sunscreen to cover 240 cm² of his skin.