Q28:

This year Henry will save a certain amount of his income, and he will spend the rest. Next year Henry will have no income, but for each dollar that he saves this year, he will have 1 + r dollars available to spend. In terms of r, what fraction of his income should Henry save this year so that next year the amount he was available to spend will be equal to half the amount that he spends this year?这题目读起来好费力啊， 能不能翻译一下啊

(1+r)*aX=(1-a)X*0.5 a=1/(3+2r)

他今年存的钱，下一年的有利息，是存的1＋r倍，这个是他下一年可以花的钱，应该等于他今年花的钱的一半。

这个意思啊，明白了，如果在考场上遇到几个这样的句子，那我的数学部分就惨了.