Một hộp có 5 bi đỏ, 4 bi xanh, 7 bi vàng và 6 bi trắng. Chọn ngẫu nhiên từ hộp ra 4 bi. Gọi X là số bi vàng trong 4 bi được chọn. Tính kỳ vọng của X.

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Một số câu hỏi khác có thể bạn quan tâm.

• Choose the best answer for the following sentence:

  Computer is an electronic ___________ which manages large collections of data.
   

• Choose the best answer for the following sentence:

  Computers allow us to exchange information ___________ a very fast rate.
   

• Choose the best answer for the following sentence:

  There are a lot of information _____________ the Internet, the matter is which one
  would you choose to read and to believe.
  
  

• Choose the best answer for the following sentence:

  Ii that the company ______________?
  
  

• Choose the best answer for the following sentence:

  A mouse is a hand - held control that lets you point to and selects items on the ___________.
   

• Choose the best answer for the following sentence:

  Many places of ____________ beauty have beer, produced by computer.
   

• Choose the best answer for the following sentence:

  Computer connected with internet can help us to send and _____________ letters easily.
  
  

• Choose the best answer for the following sentence:

  Computers are used to process information which is called _____________.
  
  

• Choose the best answer for the following sentence:

  When you are tired of hard work, you should listen to __________ music to relax.
   

• Choose the best answer for the following sentence:

  The CPU consists of two other ____________ sub-units: The Control Unit (CU) and
  the Arithmetic-Logical Unit (ALU)