SOLUTION: How many 5 digit numbers can be formed with 0,1,2,3,4,5,6,7,8,9 if (a) pre petitions are allowed, (b) repetitions are not allowed, (c) the last digit must be 2 and repetitions are

Algebra ->  Permutations -> SOLUTION: How many 5 digit numbers can be formed with 0,1,2,3,4,5,6,7,8,9 if (a) pre petitions are allowed, (b) repetitions are not allowed, (c) the last digit must be 2 and repetitions are       Log On


   



Question 1025108: How many 5 digit numbers can be formed with 0,1,2,3,4,5,6,7,8,9 if (a) pre petitions are allowed, (b) repetitions are not allowed, (c) the last digit must be 2 and repetitions are not allowed, (d) the last digit must be 2 and repetitions are allowed?
Answer by nishantxumar(3) About Me  (Show Source):
You can put this solution on YOUR website!
(a) if repetition are allowed then _ _ _ _ _ in the first space we have only 9 choice as 0 cant be considered. and for all rest 4 space we have 10 choices.... so answer becomes 9*10^4.
(b)when repetition are not allowed thn _ _ _ _ _ for the 1st space we have 9 choice.... and now we use the formula for we have to select 4 out of 9 which is 9p4 and the answer becomes 9*9*8*7*6.