SOLUTION: A science project consist of three letters followed by three digits and then three more letters. No repetition allowed in the groups, letters in the first group of three may occur

Algebra ->  Permutations -> SOLUTION: A science project consist of three letters followed by three digits and then three more letters. No repetition allowed in the groups, letters in the first group of three may occur       Log On


   



Question 785333: A science project consist of three letters followed by three digits and then three more letters. No repetition allowed in the groups, letters in the first group of three may occur also in the last group of three. How many distinct identification numbers are possible?
Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
nPr = n!/(n-r)!
26!/23!= 15600
.
10P3 = 10!/7! = 720
.
15600*720*15600=1.75*10^11
.
Ed