SOLUTION: How many 4-letter words can be formed from DESTINY? (NOTE:The word may not mean anything.) A. If repetition of the digits is permitted? B. If repetition of the digits is not p

Algebra.Com
Question 1191410: How many 4-letter words can be formed from DESTINY? (NOTE:The
word may not mean anything.)
A. If repetition of the digits is permitted?
B. If repetition of the digits is not permitted?

Answer by Edwin McCravy(20054)   (Show Source): You can put this solution on YOUR website!
How many 4-letter words can be formed from DESTINY? (NOTE:The
word may not mean anything.)
A. If repetition of the digits is permitted?
Choose the 1st letter any of 7 ways.
There are still 7 ways to choose the 2nd letter,  since you can repeat the
letter you chose first.
Choose the 2nd letter any of 7 ways.
There are still 7 ways to choose the 3rd letter, since you can repeat the
letters you chose first and second.
Choose the 3rd letter any of 7 ways.
There are still 7 ways to choose the 4th letter, since you can repeat the
letters you chose first, second, and third.
Choose the 4th letter any of 7 ways.

7x7x7x7 = 74 = 2401
B. If repetition of the digits is not permitted?
Choose the 1st letter any of 7 ways.
There are only 6 ways to choose the 2nd letter, since you cannot repeat 
the letter chosen first.
Choose the 2nd letter any of 6 ways.
There are only 5 ways to choose the 3rd letter, since you cannot repeat 
the letters chosen first or second.
Choose the 3rd letter any of 5 ways.
There are only 4 ways to choose the 4th letter, since you cannot repeat 
the letters chosen first, second or third.
Choose the 4th letter any of 4 ways.

7x6x5x4 = 840.

Edwin

RELATED QUESTIONS

From the letters of the word HONESTY,how many ways 3- letter words can be formed,if... (answered by Edwin McCravy)
From the letters of the word HONESTY, how many 3 letter words can be formed if... (answered by Edwin McCravy)
How many 4-letter combinations can be made from the word MATHLOVER if... A.) no... (answered by MathLover1,ikleyn)
How many different 4-digit numbers can be formed from the digits 2, 3,4,5,6,7, and 8 if: (answered by ewatrrr)
How many different four-letter words can be formed from the letters: a,b,c,d,e,f, and g... (answered by edjones)
HOW MANY DIFFERENT 10-LETTER WORDS(REAL OR IMAGINARY) CAN BE FORMED FROM THE LETTERS IN... (answered by Alan3354,jim_thompson5910)
How many 5-letter words can be made out of 26 letters, repetition allowed, but not... (answered by Alan3354)
how many ways 4 letter combinations can be formed out of the letters of the word... (answered by rothauserc)
How many three-digit numbers can be formed from the digits 1,2,3,4: A. If repetition of... (answered by Alan3354)