perms and combs help (2 Viewers)

[princesspiggy]

in how many ways can the letters of the word BUNDLES be arranged such that the letters B, U and N appear in that order, but not necessarily together

 

[WeiWeiMan]

in how many ways can the letters of the word BUNDLES be arranged such that the letters B, U and N appear in that order, but not necessarily together

out of the 7! ways to arrange BUNDLES, there are 3! difference ways you can arrange BUN, {ie BUN, BNU, UNB, UBN, NBU, NUB}
so 1/3! of the total arrangements of BUNDLES have BUN in that order (since all arrangements have equal probability)
hence
arrangements = 7!/3! = 840