Let 5 digit numbers be constructed using the digits 0 , 2 , 3 , 4 , 7 , 9 with repetition allowed, and are arranged in ascending order with serial numbers. Then the serial number of the number 42923 is _____ .

Step-by-step solution

Number of five-digit numbers formed using the digits 0 ,   2 ,   3 ,   4 ,   7 ,   9 with 2 at the first place is = 6 × 6 × 6 × 6 = 1296 Since, 2 + 6 + 6 + 6 + 6 = 1296 Number of five-digit numbers formed using the given digits with 3 at the first place is = 1296 Since, 3 + 6 + 6 + 6 + 6 = 1296 Number of five-digit numbers formed using the given digits with 40 at the first place is = 216 Since, 40 + 6 + 6 + 6 = 216 And, 420 + 6 + 6 = 36 4   2   2 + 6 + 6 = 36 423 +