1. The number of crimes reported in a city is 600 in 2009. If the number increased at a rate of 6% per year from 2004 to 2009, find the number of crimes reported in 2004 correct to the nearest integer.
Solution:
Let x be the number of crimes reported in 2004.
2.The value of a mobile phone is $2820 now and its value decreases by 12% per year. Find its values 3 years ago. (Give yur answers correct to the nearest integer.)
F.3 Maths
2013-07-25 11:01 pm
回答 (1)
2013-07-26 12:15 am
✔ 最佳答案
1.Let x be the number of crimes reported in 2004
x(1 + 6%)^5 = 600
x = 448
therefore the number of crimes reported in 2004 is 448
2.
Let $x be the value 3 years ago
x(1 - 12%)^3 = 2820
x = 4138
therefore the value 3 years ago is $4138
參考: knowledge
收錄日期: 2021-04-28 14:41:24
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20130725000051KK00196