AlphaBeta

第一题，设fraction 为X，每月pay为１，列方程　12X=3(1-x),x=1/5

第二题，根据题目意思，formula等于　2%*I+(100+1%*I)/2 =50+I/40

AlphaBeta

add 2 percent of one's annual income to the average (arithmetic mean) of 100 units of Country R's currency and 1 percent of one's annual income.

意思就是说把２％的收入加上　１００元和１％收入的平均数啊