In how many different ways can the letters in the word $ATTEND$ be arranged?

If $110$ triangles can be formed by joining $10$ points as vertices,in which $n$ points are collinear,then the value of $n$ is:

In how many different ways can the letters of the word '$DETAIL$' be arranged in such a way that the vowels occupy only the odd positions?

In how many ways can the letters of the word '$EXCELLENT$' be arranged?

Statement-$1$: The number of ways of distributing $10$ identical balls in $4$ distinct boxes such that no box is empty is $^9C_3$.
Statement-$2$: The number of ways of choosing any $3$ places from $9$ different places is $^9C_3$.

Six married couples decide to form a committee of $6$ persons. The total number of ways to form the committee such that it contains no couples is equal to: