請教 GWD 25-20

[Kennethy]

Based on this year'scosts,an orchade grower budgets P dollard for planting N new trees next year.If the average cost of planting each tree were to increase 25% from this year's cost ,then the greatest number of trees that the orchard grower could plant next year using P dollars would be

A.20% less than N

B.25 %less thatn N

C.equal to N

D.20% greater than N

E.25% greater than N



ANS A


WHY?? 我選e

[simonyu]

像這種比例的題目一定要用代數算，不然會被騙。

原本P元種N棵，所以每棵P/N元，漲價後為1.25*P/N元
因此P元可以種的棵樹為
P/(1.25*P/N)=0.8N
原本是N棵，現在只剩0.8N，所以減少20%，答案A