How many 5 letter password combinations can you form from 26 six letter alphabet if
b)you can use same letter only once
c)password must have exactly 2 e letters
e)password must have at least 3 e letters
+23254 I'm not sure what is meant by "26 six letter alphabet"
but in part b) if "you can use same letter only once" means that you have to use 5 different letters out of the possible 26,
I believe that the answer to this part should be: 26 x 25 x 24 x 23 x 22 = 7 893 600 ways.
+118723 How many 5 letter password combinations can you form from 26 six letter alphabet if
b)you can use same letter only once
26^5 = 11881376
c)password must have exactly 2 e letters
25^3*5C2 =
25^3*nCr(5,2) = 156250
e)password must have at least 3 e letters
25^2*nCr(5,3) = 6250 3 es
25*nCr(5,4) = 125 4 es
nCr(5,5) = 1 5es
6250+125+1 = 6376
+23254 I'm not sure what is meant by "26 six letter alphabet"
but in part b) if "you can use same letter only once" means that you have to use 5 different letters out of the possible 26,
I believe that the answer to this part should be: 26 x 25 x 24 x 23 x 22 = 7 893 600 ways.
