问题 填空题

盒子中装有8个红球和8个白球,任意摸出1个球,是红球的可能性是______,至少摸出______个球,才能保证至少有2个球的颜色相同.

答案

(1)8÷(8+8)=

1
2

(2)要保证少有两个球的颜色相同.至少应摸出2+1=3个.

答:是红球的可能性是

1
2
,至少摸出3个球,才能保证至少有2个球的颜色相同;

故答案为:

1
2
,3.

阅读理解
阅读理解。
Book: Princess Pip's Holiday(Hardcover)
By Sally Prue
Quantity Kind     Price for each book
4   new           $ 57.23
56  used          $ 23.56
Book: The King of Football (Paperback)
By Tony Bradman
Quantity Kind  
Price for each book15
15    new             $ 10.5656        
56    used            $ 6.78    
5     collectible     $ 9.56

Book: The Ghoss Ship (Paperback)  
          By Martin Waddell
Quantity Kind      Price for each book
8   new             $ 36.12
Book: My Friend, Mandela (Paperback)
By Denis Herbstein
Quantity Kind  Price for each book new
30    new             $ 35.67
26    used            $ 19.78
15    collectible    $ 20.97
1. Who is the author of the book My Friend, Mandela?    
A. Sally Prue.        
B. Denis Herbstein.    
C. Tony Bradman.      
D. Martin Waddell.
2. The price of the used book is at least _______.
A. $ 23.56    
B. $ 19.78    
C. $ 6.78    
D. $ 15.27
3. Which collectible book is the most expensive one?
A. Princess Pip's Holiday.      
B. The Ghost Ship.
C. The King of Football.          
D. My Friend, Mandela.
4. How many books of The King of Football are there on sale?
A. 25.        
B. 89.        
C. 35.        
D. 76.
5. If you want to buy a used The Ghost Ship , you will save _______.
A. $ 15.27   
B. $ 6.78   
C. $ 20.85  
D. $ 23.56
If you want to buy a used The Ghost Ship , you will save        .
A. $ 15.27   B. $ 6.78   C. $ 20.85  D. $ 23.56

单项选择题