有一條數學題目不識做

Let operation cost = x
salary expense = 0.2x
other expenses = 0.8x
New salary expense = 0.2x(1 + 10%) = (0.2x)(1.1) = 0.22x
New operation cost = 0.22x + 0.8x = 1.02x
so % of salary expense to operation cost becomes = 0.22x/1.02x
= 0.21568 = 21.568% = 21.57%

假設甲公司為x
那原來的工資支出為0.2x
正在加薪10%
(1+10%)0.2 = 0.22
所以應該係佔 22%