2002 AMC 8 第 14 题

先试着解答 2002 AMC 8 第 14 题,然后核对你的答案与精心整理的解答,解答来自 LIVE by Po-Shen Loh。你也可以参加完整限时模拟考试、查看全部 2002 AMC 8 解答,或核对答案

所有题目均经美国数学协会(MAA)官方合法授权使用。

14.

一位商人对一大批商品打 30%30\% 折扣。后来,商人又在这些促销价基础上打 20%20\% 折扣,并声称这些商品的最终价格比原价低 50%50\%。总折扣实际是

A merchant offers a large group of items at 30%30\% off. Later, the merchant takes 20%20\% off these sale prices and claims that the final price of these items is 50%50\% off the original price. The total discount is

35%35\%

44%44\%

50%50\%

56%56\%

60%60\%

答案:B
知识点:百分数
难度评级:1180
解答:

设原价为 xx。打 30%30\% 折扣后,价格是 0.70x0.70x

再从该促销价上减去 20%20\%,剩下 0.800.70x=0.56x0.80\cdot0.70x=0.56x

顾客支付原价的 56%56\%,所以总折扣是 44%44\%

所以正确答案是 B

Let the original price be xx. After the 30%30\% discount, the price is 0.70x0.70x.

Taking another 20%20\% off that sale price leaves 0.800.70x=0.56x0.80\cdot0.70x=0.56x.

The customer pays 56%56\% of the original price, so the total discount is 44%44\%.

Thus, B is the correct answer.

← 第 13 题#13
完整试卷

其他年份的第 14 题

1985 AMC 8 · 1986 AMC 8 · 1987 AMC 8 · 1988 AMC 8 · 1989 AMC 8 · 1990 AMC 8 · 1991 AMC 8 · 1992 AMC 8 · 1993 AMC 8 · 1994 AMC 8 · 1995 AMC 8 · 1996 AMC 8 · 1997 AMC 8 · 1998 AMC 8 · 1999 AMC 8 · 2000 AMC 8 · 2001 AMC 8 · 2003 AMC 8 · 2004 AMC 8 · 2005 AMC 8 · 2006 AMC 8 · 2007 AMC 8 · 2008 AMC 8 · 2009 AMC 8 · 2010 AMC 8 · 2011 AMC 8 · 2012 AMC 8 · 2013 AMC 8 · 2014 AMC 8 · 2015 AMC 8 · 2016 AMC 8 · 2017 AMC 8 · 2018 AMC 8 · 2019 AMC 8 · 2020 AMC 8 · 2022 AMC 8 · 2023 AMC 8 · 2024 AMC 8 · 2025 AMC 8 · 2026 AMC 8