What is the halving and doubling strategy

How many square feet of out door carpet will we need for this hole? 8ft 3ft 12ft 4ft

Yoku is putting on sunscreen. he uses 2\text{ ml}2 ml to cover 50\text{ cm}^250 cm 2 of his skin. he wants to know how many milliliters of sunscreen (c)(c) he needs to cover 325\text{ cm}^2325 cm 2 of his skin. how many milliliters of sunscreen does yoku need to cover 325 \text{ cm}^2325 cm 2 of his skin?

Adozen bananas weigh 3 pounds how many ounces does 1 banana weigh