Q15 / 120 · NDA 2024 (Phase 2) · Mathematics
The letters of the word EQUATION are arranged in such a way that all vowels as well as consonants are together. How many such arrangements are there?
- Correct answerA$240$
- B$720$
- C$1440$
- D$1620$
Solution
Here, word, 'EQUATION' contains 5 vowels (A, E, I, $\mathrm{O}, \mathrm{U})$ and 3 consonants ( $\mathrm{Q}, \mathrm{T}, \mathrm{N}$ ).
Two cases are possible here
Case (I):

$\begin{aligned} & \text { Number of ways for this arrangement }=(3!) \cdot(5!) \\ & \text {Case(II): }\end{aligned}$
$\begin{aligned} & \text { Number of ways for this arrangement }=(3!) \cdot(5!) \\ & \text {Total required number of ways }=(3!)(5!)+(3!)(5!) \\ & =1440\end{aligned}$

$\begin{aligned} & \text { Number of ways for this arrangement }=(3!) \cdot(5!) \\ & \text {Case(II): }\end{aligned}$

$\begin{aligned} & \text { Number of ways for this arrangement }=(3!) \cdot(5!) \\ & \text {Total required number of ways }=(3!)(5!)+(3!)(5!) \\ & =1440\end{aligned}$
Hence, the correct answer is option: 'A'.