问题 解答题

我市一家电子计算器专卖店每只进价13元,售价20元,多买优惠;凡是一次买10只以上的,每多买1只,所买的全部计算器每只就降低0.10元,例如,某人买20只计算器,于是每只降价0.10×(20﹣10)=1(元),因此,所买的全部20只计算器都按照每只19元计算,但是最低价为每只16元。

(1)求一次至少买多少只,才能以最低价购买?

(2)写出该专卖店当一次销售x时,所获利润y(元)与x(只)之间的函数关系式,并写出自变量的取值范围;

(3)若店主一次卖的只数在10至50只之间,问一次卖多少只获得的利润最大?其最大利润为多少?

答案

解:(1)设一次购买x只,才能以最低价购买,依题意,得

0.1(x-10)=20-16,

解这个方程得x=50,

答:一次至少买50只,才能以最低价购买;

(2)

(3)∵依得意,

∴ 配方得

∴店主一次卖40只时可获得最高利润,最高利润为160元。

填空题
阅读理解

The old shopkeeper led me through to the back of the shop. The room was filled with boxes and photographs of people dressed in old-fashioned clothes, holding packages in their hands.

“Who are these people?” I asked.

“Satisfied customers,” answered young Mr. Hopkins. “We have a very wide choice of items for sale. Whenever I serve a new customer, I always take their picture.” Mr. Hopkins pointed to an ancient camera standing next to one wall. “Now, how can I serve you?” he added.

By this time, I had started to trust Mr. Hopkins and had begun to appreciate the lovely items on sale. I needed to buy Christmas presents for my family and friends, and this seemed to be the perfect place to purchase them. I spent a very pleasant hour being shown the commodities in Mr. Hopkins’shop. No matter what I asked for, Mr. Hopkins found it for me. Finally, I bought an antique jewelry box, a pair of riding boots, a leather-bound edition of the Complete Works of Mark Twain, and a sewing machine.

I was very excited that I had found such a good little shop. I promised Mr. Hopkins that I would come back soon. “I will tell all my friends about your lovely place,” I told the shopkeeper.

“Please do not do that, sir”, said Mr. Hopkins. “This is a special place for special people. You must keep this shop a secret.” Then he took my photograph, and handed me the picture straight away.

“That was quick!” I exclaimed. I looked at the photograph. In the picture I looked proud and excited holding the presents I had bought in Mr. Hopkins’ dusty shop.

On Christmas Day, my friends and relatives were delighted with the presents I had bought for them. For weeks, my brother begged me to show him where to find this wonderful little shop. I finally agreed to take him to London to show him.

When we arrived in London, we walked along Oxford Street, past the department store and found...nothing. The little shop was no longer there. In its place was an empty space being used as a car park. I checked the area again. There was the music shop, and there was the department store. In between should have been Hopkins and Son, but it wasn’t there.

As I was staring at the place where the shop should have been, an old policeman came along. “Are you looking for something sir?” he asked.

I turned and said “I am looking for a little shop called Hopkins and Son. I thought it was here.”

“Oh yes,” said the policeman. “There was a shop here once called Hopkins and Son. It sold all sorts of things, but it was knocked down over 30 years ago.”

I looked again at the place where the shop had been. Then I reached into my pocket and took out the photograph that Mr. Hopkins had taken of me holding my presents in the little shop.

“How strange” I exclaimed.

小题1:How did the writer like the shop?

A.He found it a modern big shop.

B.He thought it a wonderful shop for all Christmas presents.

C.He thought it a good shop with an ancient camera.

D.He found it a dusty, old but friendly and lovely little shop.小题2:Which of the following is true about the shop?

A.It was knocked down a few weeks ago.

B.It was a well-known little shop in London.

C.It was a special shop selling special presents.

D.It was between a music shop and a department store.小题3:The word “the commodities’ in the 4th paragraph means _____.

A.the writer’s works

B.the goods in the shop

C.Mr. Hopkins’ photographs

D.Some presents left by other customers小题4:Which of the following is the best title of this passage?

A.Christmas Shopping

B.Hopkins and His Son

C.The Strange Little Shop

D.The Strange Experience