Prep-T1-Ds-Q215

[lucyyeh]

215. 20843-!-item-!-187;#058&013306
If Bob produces 36 or fewer items in a week, he is paid x dollars per item. If Bob produces more than 36 items in a week, he is paid x dollars per item for the first 36 items and 1.5 times that amount for each additional item. How many items did Bob produce last week?

(1) Last week Bob was paid a total of $480 for the items that he produced that week.

(2) This week Bob produced 2 items more than last week and was paid a total of $510 for the items that he produced this week.


ANS: E

不解阿，我算出x等於10，做36+8個就可以符合了，不知道為什麼答案是E???

[austi_co]

小弟假設 上一周做了Y個items
薪水可能有兩種算法
XY = 480 (Y如果小於36)
XY + 1.5X (36 - Y) = 480 (Y如果大於36)

那這一周也是如此
X (Y + 2) = 510(Y + 2 如果小於36)
X (Y + 1) + 1.5X = 510(剛好超過一個)
XY + 1.5X(2) = 510(剛好超過二個)
XY + 1.5X(36 - <Y+2>) = 510(Y本來就大於36)

小弟個人覺得Y值的不確定...會造成很多的可能性
但依照(1)(2)的要件來說
Y值的可能性就有上述幾種
所以條件不足...選E

初淺的想法..請見諒

[lucyyeh]

謝謝~ 果然我又是沒想清楚，中秋連假還有AT戰友支持真是感人。

[Huang Hsin-Yi]

215. E 此題需要把低於36個 或多於36個想進去
If Bob produces 36 or fewer items in a week, he is paid x dollars per item. If Bob produces more than 36 items in a week, he is paid x dollars per item for the first 36 items and 1.5 times that amount for each additional item. How many items did Bob produce last week?

(1) Last week Bob was paid a total of $480 for the items that he produced that week.
設last week =y item
if y<36 -->xy=480
if y>36--> 36x+1.5x(y-36)=480

(2) This week Bob produced 2 items more than last week and was paid a total of $510 for the items that he produced this week.
This week =y+2
If y+2<36--> x(y+2)=510
if y+2>36--> 36x+1.5x(y-34)=510


therefore
if y<36 combine (1)(2) x=15 y=32
ify>36 combine (1)(2) x=10 y=44

Ans: E