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How many different 10 digit phone numbers are possible if the 1st digit can be 0, 2nd digit can be 9 and the 3rd digit can be either 1 or 2 or 3?

Respuesta :

Answer:

30000000

Step-by-step explanation:

there are 10 digits in the phone number

and phone numbers repeat numbers so u can have 9999999999 if that is the case

first digit must be 0 (1 pn (possible numbers)

second digit must be 2 ( 1 pn

third digit must be either 1 or 2 or 3 ( 3 pn )

Since repeated is allowed 4 to 10th digit can be any number from 0-9(10 pn)

therefore total possible numbers is

1*1*3*10*10*10*10*10*10*10 = 3*10⁷