标题: 一道prep关于比例的数学题，求解 [打印本页] 作者: norris1938 时间: 2016-7-18 07:53 标题: 一道prep关于比例的数学题，求解 Last year, sales at Company X were 10% greater in February than in January, 15% less in March than in February, 20% greater in April than in March, 10% less in May than in April, and 5% greater in June than in May. On which month were sales closes to the sales in January?
请问NN有没有什么好的解题方法？可以在考场上用的方法 作者: ccp92 时间: 2016-7-18 09:45
你先设一个起始数，比如一月的sales是x，然后其他月的sales都可以算啦作者: CaesarMBA 时间: 2016-7-18 10:54
On which month were sales closes to the sales in January? --> Assume the sales in Jan. is “a”
10% greater in February than in January, --> Sales in Feb. is 1.1a
15% less in March than in February, --> Sales in Mar is 1.1a * 0.85
20% greater in April than in March, --> Sales in Apr is 1.1a * 0.85 *1.2
10% less in May than in April, --> Sales in May is 1.1a * 0.85 *1.2 * 0.9
and 5% greater in June than in May. --> Sales in Jun is 1.1a * 0.85 *1.2 * 0.9 *1.05