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Consider the phone number 289-3447. how many alphabetic phone numbers can be made from this number using the letters on the phone buttons? For example, BUY-EGGS is one possibility and ATX-DIGR is another.

2 , 8 , 3 , 4 HAVE 3 ALPHABETS....OVER THEM......7 & 9 HAVE 4 ALPHABETS OVER THEM .......ASSUMING NO REPETETION IS ALLOWED [ EXCEPT IN THE CASE OF 44 REPETETION AS GIVEN ] ..WE HAVE

FOR THE GIVEN .....289-3447 NUMBER .....3*3*4*3*3*3*4 = 3888 POSSIBILITIES

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b) Answer the same question if you're allowed the option of leaving numbers unchanged, like C8Y-F4IP........

THAT IS FOR EACH OF THE LETTERS WE SHALL HAVE AN ADDITIONAL OPTION ...

SO WE GET ....

FOR THE GIVEN .....289-3447 NUMBER .....4*4*5*4*4*4*5 = 25600 POSSIBILITIES