AMC10 2018 B

AMC10 2018 B · Q1

AMC10 2018 B · Q1. It mainly tests Basic counting (rules of product/sum), Area & perimeter.

Kate bakes a 20-inch by 18-inch pan of cornbread. The cornbread is cut into pieces that measure 2 inches by 2 inches. How many pieces of cornbread does the pan contain?

Kate烤了一个20英寸×18英寸的玉米面包盘。玉米面包被切成2英寸×2英寸的块。这个盘子包含多少块玉米面包？

(A) 90 90

(B) 100 100

(D) 200 200

(E) 360 360

Answer

Correct choice: (A)

正确答案：（A）

Solution

The total area of cornbread is 20 · 18 = 360 in². Because each piece of cornbread has area 2·2 = 4 in², the pan contains 360 ÷ 4 = 90 pieces of cornbread.

玉米面包的总面积是20 · 18 = 360 in²。每块玉米面包的面积是2·2 = 4 in²，因此盘子包含360 ÷ 4 = 90块玉米面包。或者切割时，长边有20 ÷ 2 = 10块，短边有18 ÷ 2 = 9块，所以总共有10 · 9 = 90块。

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