求解一道数学题

小山香满蔽高岑

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. In which month were sales closest to the sales in January?


这道题的答案不应该是Apr吗？对应一月的0.99。
官方的答案给的是May。

小山香满蔽高岑

雁十九 发表于 2019-12-22 14:44
就是May。对应的一月应该是“单位一”才对。
假设1月销售额是J，2月就是是1.1J， 3月是0.85*1.1J=0.935J, 4 ...

谢谢你。

要过G马特

还以为是今天的输血JJ呢。。。。。。。

雁十九

就是May。对应的一月应该是“单位一”才对。
假设1月销售额是J，2月就是是1.1J， 3月是0.85*1.1J=0.935J, 4月是1.2*0.935J=1.122J, 5月是0.9*1.122J=1.0098J。6月没必要算了，比五月还多是不可能更接近于J的。
我感觉你审错题了吧应该是，sales at Company X were 10% greater in February than in January说的是X公司2月份的销售额比1月份增长了10%，【10% GREATER IN A THAN IN B：B=(1+10%)A 】。