Question

Find the sum of five digit numbers that can be formed using 1,2,3,4,5

Answer 1

Answer:

Step-by-step explanation:

number of ways in which 1,2,3,4,5 can be arranged is 120. If we keep 5 at the last place i.e. 10000th then number of ways in which the other 4 numbers can be arranged is 24 hence, 5 will come at the 10000th place 24 times similarly for all other positions of 5 that is 5(24+240+2400+24000+240000)

similarly for all other numbers, (1+2+3+4+5) (24+240+2400+24000+240000)=3999960...