1
COMEDK 2026 Morning Shift
MCQ (Single Correct Answer)
+1
-0

An engineering team is testing a new prototype drone. The drone has constant success rate of $\frac{\mathbf{2}}{\mathbf{7}}$ for every autonomous landing attempt. Two engineers, Sarah and Swarna, take turns initiating the landing sequence, with Swarna going first.

If they continue the process until a landing is successful, what is the probability that Sarah is the one who initiates the successful landing?

A

$\frac{5}{12}$

B

$\frac{30}{37}$

C

$\frac{7}{37}$

D

$\frac{7}{12}$

2
COMEDK 2026 Morning Shift
MCQ (Single Correct Answer)
+1
-0

Let ' $\boldsymbol{a}$ ' and ' $\mathbf{b}$ ' be two numbers where $\boldsymbol{a}<\boldsymbol{b}$. The geometric mean of these numbers exceeds the smaller number by 12 and the arithmetic mean is smaller than the larger number by 24 . Then the value of $|\boldsymbol{b}-\boldsymbol{a}|$ is:

A

52

B

44

C

48

D

60

3
COMEDK 2026 Morning Shift
MCQ (Single Correct Answer)
+1
-0

$$ \text { The expression } \frac{1-\tan ^2\left(\frac{\pi}{4}-A\right)}{1+\tan ^2\left(\frac{\pi}{4}-A\right)} \text { equals } $$

A

$\sin A$

B

$\sin 2 A$

C

$\cos A$

D

$\cos 2 A$

4
COMEDK 2026 Morning Shift
MCQ (Single Correct Answer)
+1
-0

The behaviour of the function $f(x)=\sin \left(2 x+\frac{\pi}{4}\right)$ on $\left(\frac{3 \pi}{8}, \frac{5 \pi}{8}\right)$ is:

A

Strictly increasing on $\left(\frac{3 \pi}{8}, \frac{5 \pi}{8}\right)$

B

Strictly increasing on $\left(\frac{\pi}{8}, \frac{3 \pi}{8}\right)$

C

Strictly decreasing on $\left(\frac{3 \pi}{8}, \frac{5 \pi}{8}\right)$

D

${\text { Strictly decreasing on }}\left(\frac{\pi}{8}, \frac{5 \pi}{8}\right)$