问题 解答题

某蔬菜公司收购到某种蔬菜140吨,准备加工后上市销售.已知每吨蔬菜粗加工后的利润为1000元,精加工后为2000元,该公司的加工能力是:每天可以精加工6吨或者粗加工16吨.现有15天时间可以用来加工这种蔬菜.如何合理安排粗加工和精加工的时间,才能使公司恰好在15天内将蔬菜全部加工完?该公司出售这些加工后的蔬菜共可获利多少元?

答案

设应安排x天精加工,y天粗加工.根据题意,

x+y=15
6x+16y=140
.(2分)

解这个方程组,得

x=10
y=5
.(4分)

出售这些加工后的蔬菜一共可获利:2000×6×10+1000×16×5=200 000(元)(5分)

答:安排10天精加工,5天粗加工可按期完成加工任务,此时共可获利200 000元.(6分)

单项选择题 A1/A2型题
单项选择题

Lying in the sun on a rock, the cougar saw Jeb and his son, Tom, before they saw it. Jeb put his bag down quickly and pulled his jacket open with both hands, making himself look big to the cougar. It worked. The cougar hesitated, ready to attack Jeb, but ready to forget the whole thing, too.
Jeb took off his jacket, grasped Tom and held him across his body, making a cross. Now the cougar’s enemy looked even bigger, and it rose up, ready to move away, but unfortunately Tom got scared and struggled free of Jeb.
"Tom, No !" shouted his father.
But Tom broke and ran and that’s the last thing you do with a cougar. The second Tom broke free, Jeb threw himself on the cougar, just as it jumped from the rock. They hit each other in mid air and both fell. The cougar was on Jeb in a flash, forgetting about Tom, which was what Jeb wanted. Cougars are not as big as most people think and a determined man stands a chance, even just with his fists. As the cougar’s claws got into his left shoulder, Jeb swung his fist at its eyes and hit hard. The animal howled(吼叫) and put its head back. Jeb followed up with his other fist. Then out of the corner of his eye, Jeb saw Tom. The boy was running back to help his father.
"Knife, Tom," shouted Jeb.
The boy ran to his father’s bag, while Jeb started shouting as well as hitting, to keep the cougar’s attention away from Tom. Tom got the knife and ran over to Jeb. The cougar was moving its head in and out, trying to find a way through the wall. Jeb was making out of his arms. Tom swung with the knife, into the cougar’s back. It howled horribly and ran off into the mountains.

How did Jeb try to hold the cougar’s attention

A.By keeping shouting and hitting.
B.By making a wall out of his arms.
C.By throwing himself on the cougar.
D.By swinging his fists at the cougar’s eyes.