.
(a) There are 7 letters, in all.
Of them, letter "C" has multiplicity 2, and
letter "N" has multiplicity 2.
THEREFORE, the formula and the answer for this question are
= = 1260. ANSWER
Solved, answered and explained.
See the lesson
- Arranging elements of sets containing indistinguishable elements
in this site.
==============
(b) = 7! = 7*6*5*4*3*2*1 = 5040 different ways. ANSWER
Solved.
See the lesson
- Persons sitting around a cicular table
in this site, and learn the subject from there.
Also, you have this free of charge online textbook in ALGEBRA-II in this site
- ALGEBRA-II - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Combinatorics: Combinations and permutations".
Save the link to this textbook together with its description
Free of charge online textbook in ALGEBRA-II
https://www.algebra.com/algebra/homework/complex/ALGEBRA-II-YOUR-ONLINE-TEXTBOOK.lesson
into your archive and use when it is needed.