gre数学提问
题目1：Atasale,thecostofeachtiewasreducedby20%andthecostofeachbeltwasreducedby30%
Thepercentreductiononthetotalcostof1tieand2belts和25%比较大小
题目2：Forthelinewithequationy=ax+b,ab不为零thexinterceptistwicetheyintercept
Theslopeoftheline和1/2比较大小
付光远回答：
[Problem1]
Solution:
1tie:Originalprice:t
Reducedby:0.2t
2belts:Originalprice:2b
Reducedby:0.6b
Thepercentagereduction=(0.2t+0.6b)/(t+2b)=0.2x(1+1/(2+t/b))
So20%
陈德军回答：
楼上给的是正确的…………第一题和第二题都是D
相关文章：
