prep 176 数学求解！

echo19872010

176. 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 amunt of money that she had saved at the end of the year was 3 times the amount of that portion of her monthly take-home pay that she did not save. if all the money that she saved lat year was from her take-home pay, what fraction of her take-home pay did she save each month?

1/2; 1/3; 1/4; 1/5; 1/6

the answer is 1/5, why?

echo19872010

多谢 ！果然是没看清fraction这个单词导致整题理解错误。

onedayling

主要是第二句话你要读懂然后列方程。

onedayling

设fraction是X，她月收入是Y, 那么可以根据题意列方程12?Y?x=3?(1-x)y,得x为1／5。

YINDAPENG

the sentence in line 2----“3 times the amount of that portioon of her monthly take-home pay that she did not save"

"the amount" in the sentence above is indicated  the monthly amount not the total amount in a year