PP-T1-PS62

[Huang Hsin-Yi]

62. 7564-!-item-!-187;#058&005577
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 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 last year was from her take-home pay, what fraction of her take-home pay did she save each month?

Ans:1/5

[nemolee]

題問每月存的錢佔了實際收入多少% ?
設：每個月存入 x 元，沒有存入的拿去吃吃喝喝又玩樂的有 y 元
12x = 3y ==>(1年有12個月，題又說全年存的$$是沒存的三倍)
簡化後則 y = 4x
題目問比率：x / (x + y) ==> 將y=4x代入後 ==> x / ( x + 4x) = x / 5x = 1/5

[Huang Hsin-Yi]

謝謝囉!