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Ten digit telephone number has a form (XYZ) - ABC-DEFG. In the particular state there are 4 possible area codes (404, 470, 678, and 770). The digit A is restricted to a number 2 through 7. The digits B, C, and D can be any number but they cannot repeat. E,F, G have no restrictions. How many phone numbers are possible with these restrictions?

 Oct 7, 2020
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area         A          B    C   D   E   F   G

  4       x   6      x  10 * 9  *8 *10*10*10  =........

 Oct 7, 2020

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