小升初奥数题（英文版）3

　　1、An ant covers a distance of 90 metres in 3 hours. The average speed of the ant in decimetres per minute is____.

　　2、

　　3、In a certain town some people were affected by a ’flu’ epidemic. In the first month 20% of the population contracted the flu whilst 80% were healthy.In the following month 20% of the sick people recovered and 20% of the healthy people contracted the disease.What fraction of the population is healthy at the end of the second month?

　　4、Mpho, Barry, Sipho, Erica and Fatima are sitting on a park bench.Mpho is not sitting on the far right. Barry is not sitting on the far left.Sipho is not sitting at either end. Erica is sitting to the right of Barry,but not necessarily next to him. Fatima is not sitting next to Sipho.Sipho is not sitting next to Barry.Who is sitting at the far right?

　　5、Of the 28 T?shirts in a drawer, six are red, five are blue, and the rest arewhite. If Bob selects T?shirts at random whilst packing for a holiday, what is the least number he must remove from the drawer to be sure that he has three T?shirts of the same colour?

　　6、In an alien language, jalez borg farn means “good maths skills”. Nurf klar borg means“maths in harmony” and darko klar farn means “good in gold”.What is “harmony gold” in this language?

　　7、Five children, Amelia, Bongani, Charles, Devine and Edwina, were in the classroom when one of them broke a window. The teacher asked each of them to make a statement about the event, knowing that three of them always lie and two always tell the truth. Their statements were as follows:Amelia: “Charles did not break it, nor did Devine.”Bongani: “I didn’t break it, nor did Devine.”Charles: “I didn’t break it, but Edwina did.”Devine: “Amelia or Edwina broke it.”Edwina: “Charles broke it.”Who broke the window?

　　8、Did you know? A palindrome is a number which reads the same forwards as backwards e.g. 35453. Next year 2002 is an example of a palindromic number. What is the difference between 2002 and the number of the previous palindromic year?

　　9、If a ?b = (2×a)?(3×b) then the value of 2 ?(3 ?5) is____.

　　10、Two ants start at point A and walk at the same pace. One ant walks around a 3 cm by 3 cm square whilst the other walks around a 6 cm by 3 cmrectangle. What is the minimum distance, in centimetres, any one mustcover before they meet again?

　　参考答案：

　　1、 单位换算，注意单词，90×10÷（3×60）＝5

　　2、 46

　　3、 0.68

　　4、 Erica

　　5、 抽屉原则 7

　　6、 注意一一对应，borg= maths, farn=good, jalez=skills. Klar=in, Nurf=harmony, darko=gold. 答案是Nurf darko.

　　7、 Charles

　　8、 1001

　　9、 67

　　10、 108