请教猴哥112数学难题第89题(具体见内)
Rack A holds 80 pairs of slacks with prices ranging from $12 to $15 a pair, and rack B holds 60 pairs of slacks with prices ranging from $13 to $18 a pair. If all the slacks are sold, what is the greatest amount by which the revenue from the sale of slacks on rack A could possibly exceed the revenue from the sale of slacks on rack B?A $430
B $412
C $122
D $120
E $112
答案是B。但是我计算出来为什么是420呢?12*80 - 13*60 = 420。应该怎样做此题?
谢谢大家 8-) :) , 极端情况就是,RANGE A 一双13,其余15, RANGE B 一双18, 其余13
记住看清RANGE FROM
15*79+12-13*59-18=412 15*79+12-59*13-18 谢谢大家。原来这题有这么大一个陷阱。 前辈,求问陷阱是什么?range from A to B 我以为就是取值范围的意思,难道还有什么深意?求教为何不是420!
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