Question

How many different arrangements can be made by taking $5$ of the letters of the word equation?

Answer 1

There are $8$ letters in the word $equation$ and the number of ways of selecting 5 letters $={}^8{C}_5$

The arrangement of $5$ letters is $=5!$.

The total different arrangements will be $={}^8{C}_5\times 5!$

$=8\times 7\times 6\times 5\times 4$

$=6720$