prep-PS-62

hahawe

Alice's take-home pay last year was the same each month, and she saved the same fraction of her take-home pay each month. The total amount of money that she saved at the end of the year was 3times the amount of that portion of her monthly thake-home pay that she did not save. If all the money that she saved last year was from her take-home pay, what fracion of her take-home pay did she save each month?
KEY:1/5

lisalee

同问

篮球火

思路：设每个月save=x，take-home pay=y，由第二句话12x=3（y-x），解得x/y=1/5

worker

设Alice每月的take-home pay是A，每个月省下来的钱是xA，没省下来的就是(1-x)A
根据题意，12xA=3A(1-x)  
解得  x=1/5