Q205 / 270 · NDA 2022 (Phase 1) · Mathematics
Consider the inequations $5 x-4 y+12 \lt 0, x+y \lt 2, x \lt 0$ and $y \gt 0$. Which one of the following points lies in the common region?
- A$(0,0)$
- B$(-2,4)$
- C$(-1,4)$
- Correct answerD$(-1,2)$
Solution
(a) $\because x \gt 0$ and $y \gt 0$
So $(0,0)$ not lies in region
(b) $-2+4=2$ is not less than 2
So, $(-2,4)$ not lies in region
(c) $-1+4=3 \gt 2$
So, $(-1,4)$ not lies in region
(d) $-1+2=1 \lt 2$
and $5(-1)-4(2)+12=-5-8+12=-1 \lt 0$
Since, satisfy all inequation So, $(-1,2)$ lies in region
Hence, the correct answer is option: 'D'.