I think its more then 20
5 digit telephone numbers having at least one of their digits repeated is = total possible 5 digit telephone numbers - 5 digit telephone numbers without any digit being repeated. =(10*10*10*10*10)-(10*9*8*7*6) =100000-30240 =69760
10234
1023
1023
I think its more then 20
5 digit telephone numbers having at least one of their digits repeated is = total possible 5 digit telephone numbers - 5 digit telephone numbers without any digit being repeated. =(10*10*10*10*10)-(10*9*8*7*6) =100000-30240 =69760
10234
1023
1023
0.124
0.467
17,059 x 6 = 102,354
1,024 ! (One thousand twenty four)
100
There are a total of 900 3-digt numbers (100 thru 999); Of these there are 9x9x8 = 648 numbers that do not contain repeating digits (first position: 9 possibilities, second place 9 possibilities; the 10 digits minus the one used in the first place. and third place 8 possibilities; 10 digits minus the two used in the first and second places) So, there should be 900-648=252 3-digit numbers with at least one repeating digit.
When multiplying numbers with different numbers of significant digits, the result should have the same number of significant digits as the least precise measurement. Count the number of significant digits in each number, perform the multiplication as usual, and then round the result to the least number of significant digits used in the calculation.