In May Mrs. Lee's earnings were 60 percent of the Lee family's total income. In June Mrs. Lee earned 20 percent more than in May. If the rest of the family's income was the same both months, then, in June, Mrs. Lee's earnings were approximately what percent of the Lee family's total income?
没看到the rest，默认为total income不变。。。

到6月总数也变了2/（72+40）=64%

理解题意，五月份，mrs/total=60%，设五月total=100，则五月mrs=60，五月rest=40（每个月rest不变）六月，mrs=60*1.2=72，占total比例=72/（72+40）=64%

分母是会 变的

哎，到6月总数也变了。分母变了所以不是72%！

哎，到6月总数也变了。分母变了所以不是72%！

the rest of the family's income was the same both months!!!!!!

Let total income of the family be 100$. In May Mrs Lee's earnings were 60 percent = 60$. Rest of the family's earnings = 40$.

In June family's earnings did not change = 40$, Mrs Lee's earnings = 60$*1.2 = 72$. Total = 40 + 72 = 112$. Mrs Lees share = 72/112=64%

全家revenue in May is A, Lee in may earned 0.6A, in June is 0.6A*1.2=0.72A, in June， family total is 0.4A+0.72A. 0.71/1.12=64%. If the rest of the family's income was the same both months, understand it carefully,

假設Lee全家所得為x, 則五月份Lee單所得 0.6x, 其他所得為0.4x。六月份Lee單所得為: 0.72x (o.6*1.2)，所以六月份Lee所得佔全家所得的百分比為:
(0.72x)/(0.72x+0.4x)=0.64