AMC8 2020

AMC8 2020 · Q3

AMC8 2020 · Q3. It mainly tests Unit conversion, Area & perimeter.

Carrie has a rectangular garden that measures $6$ feet by $8$ feet. She plants the entire garden with strawberry plants. Carrie is able to plant $4$ strawberry plants per square foot, and she harvests an average of $10$ strawberries per plant. How many strawberries can she expect to harvest?

Carrie 有一个 6 英尺乘 8 英尺的长方形花园。她在整个花园里种满了草莓植株。Carrie 每平方英尺能种 4 株草莓植株，她每株植株平均收获 10 个草莓。她能期望收获多少草莓？

(A) 560 560

(B) 960 960

(D) 1920 1920

(E) 3840 3840

Answer

Correct choice: (D)

正确答案：（D）

Solution

Note that the unit of the answer is strawberries, which is the product of By conversion factors, we have \[\left(6 \ \color{red}\cancel{\mathrm{ft}}\color{black}\cdot8 \ \color{red}\cancel{\mathrm{ft}}\color{black}\right)\cdot\left(4 \ \frac{\color{green}\cancel{\mathrm{plants}}}{\color{red}\cancel{\mathrm{ft}^2}}\right)\cdot\left(10 \ \frac{\mathrm{strawberries}}{\color{green}\cancel{\mathrm{plant}}}\right)=6\cdot8\cdot4\cdot10 \ \mathrm{strawberries}=\boxed{\textbf{(D) }1920} \ \mathrm{strawberries}.\]

注意答案的单位是草莓，这是以下乘积：通过单位换算，我们有 \[\left(6 \ \color{red}\cancel{\mathrm{ft}}\color{black}\cdot8 \ \color{red}\cancel{\mathrm{ft}}\color{black}\right)\cdot\left(4 \ \frac{\color{green}\cancel{\mathrm{plants}}}{\color{red}\cancel{\mathrm{ft}^2}}\right)\cdot\left(10 \ \frac{\mathrm{strawberries}}{\color{green}\cancel{\mathrm{plant}}}\right)=6\cdot8\cdot4\cdot10 \ \mathrm{strawberries}=\boxed{\textbf{(D) }1920} \ \mathrm{strawberries}.\]

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