Q244 / 270 · NDA 2023 (Phase 2) · Mathematics
The vectors $60 \hat{i}+3 \hat{j}, \quad 40 \hat{i}-8 \hat{j} \& \beta \hat{i}-52 \hat{j}$ are collinear if:
- A$\beta=20$
- B$\beta=40$
- Correct answerC$\beta=-40$
- D$\beta=26$
Solution
For collinear of given vectors
$\begin{aligned}
& \frac{-8-3}{40-60}=\frac{-52+8}{\beta-40} \\
& \Rightarrow \frac{-11}{-20}=\frac{-44}{\beta-40} \\
& \Rightarrow \beta-40=-80 \\
& \Rightarrow \beta=-40
\end{aligned}$
Hence, the correct answer is option: 'C'.