CDS Exam (II)- 2023 - Elementary Mathematics Defence Question Paper

CDS Previous Year Question Papers Question Papers
CDS Exam (II)- 2023 - Elementary Mathematics

CDS Exam (II)- 2023 - Elementary Mathematics Defence Questions

11.
How many real roots does the equation \( \sqrt{x + 9} = x - 3 \) have?
A.
Only one
B.
Only two
C.
Only three
D.
None
ANSWER :
A. Only one
12.
If \( x = 97 + 56\sqrt{3} \), then what is the value of \( \sqrt[4]{x} + \frac{1}{\sqrt[4]{x}} \)?
A.
7
B.
6
C.
5
D.
4
ANSWER :
D. 4
13.
Let L be the LCM and H be the HCF of two given numbers. L and H are in the ratio 6 : 1. If the sum of the two numbers is 45, then what is the product of the numbers?
A.
243
B.
486
C.
504
D.
Cannot be determined due to insufficient data
ANSWER :
B. 486
14.
A man walks at an average speed of 3 km/hr from his home and reaches office 40 minutes early. If he walks at an average speed of 2 km/hr, he would reach office 40 minutes late. What is the distance between his home and office?
A.
6 km
B.
8 km
C.
10 km
D.
12 km
ANSWER :
B. 8 km
15.
If \( 3^{x - 1} + 3^{3 - x} = 6 \), then what is \( 2^{x - 1} + 2^{3 - x} \) equal to?
A.
4
B.
3
C.
2
D.
1
ANSWER :
A. 4
16.
If \( x\left(a - b + \frac{ab}{a - b}\right) = y\left(a + b - \frac{ab}{a + b}\right) \) and \( x + y = 2a^{3} \), then what is \( x - y \) equal to?
A.
\( -2b^{3} \)
B.
\( -2ab^{3} \)
C.
\( 2b^{3} \)
D.
\( 2ab^{3} \)
ANSWER :
A. \( -2b^{3} \)
17.
Which one of the following is a factor of \( 3\sqrt{3}x^{3} + 2\sqrt{2}y^{3} - 18xy + 6\sqrt{6} \)?
A.
\( \sqrt{3}x + \sqrt{2}y - \sqrt{3} \)
B.
\( \sqrt{3}x + \sqrt{2}y - \sqrt{6} \)
C.
\( 3x^{2} + 2y^{2} - \sqrt{18}x - \sqrt{12}y - \sqrt{6}xy + 6 \)
D.
\( 3x^{2} + 2y^{2} + \sqrt{18}x + \sqrt{12}y - \sqrt{6}xy + 6 \)
ANSWER :
C. \( 3x^{2} + 2y^{2} - \sqrt{18}x - \sqrt{12}y - \sqrt{6}xy + 6 \)
18.
What is number of digits in the expansion of \( 125^{100} \)? (Given \( \log_{10} 2 = 0.301 \))
A.
69
B.
70
C.
209
D.
210
ANSWER :
D. 210
19.
What is the HCF of
\( acx^{3} + bcx^{2} + adx^{2} + acdx + bdx + bcd \) and
\( adx^{3} + acx^{2} + bdx^{2} + bcx + acdx + bcd \)
if HCF \( (c, d) = 1, c \neq d \)?
A.
\( bx + c \)
B.
\( cx + d \)
C.
\( ax + d \)
D.
\( ax + b \)
ANSWER :
D. \( ax + b \)
20.
If \( x^{n} - py^{n} + qz^{n} \) is divisible by \( x^{2} + abyz - bzx - axy \), then what is \( \frac{p}{a^{n}} - \frac{q}{b^{n}} \) equal to?
A.
-1
B.
0
C.
1
D.
2
ANSWER :
C. 1