CDS Exam (II)- 2026 - Elementary Mathematics Defence Question Paper

CDS Previous Year Question Papers Question Papers
CDS Exam (II)- 2026 - Elementary Mathematics

CDS Exam (II)- 2026 - Elementary Mathematics Defence Questions

21.
A shopkeeper sold his goods at the cost price. By using false weights, he gained \( 11\frac{1}{9} \)%. What weight did he use for 1 kg?
A.
960 gm
B.
950 gm
C.
925 gm
D.
900 gm
ANSWER :
D. 900 gm
22.
If the roots of the equation \( px^{2} - 40x + 96 = 0 \) are even integers, then what is the value of p?
A.
1
B.
2
C.
3
D.
4
ANSWER :
D. 4
23.
A number N consists of two digits. The digit in the tens place is 3 times the digit in the units place. The digits are reversed and the resulting number is denoted by R. If \( N \times R = 3627 \), then what is the product of the digits of the number N?
A.
27
B.
18
C.
12
D.
3
ANSWER :
A. 27
24.
A boatman can row to a place (Y) at a distance of 24 km from the starting point (X) and back in 14 hours. If he can row 4 km with the stream in the same time as 3 km against it, what is the speed of the stream?
A.
0.5 km/hr
B.
1 km/hr
C.
2 km/hr
D.
2.5 km/hr
ANSWER :
A. 0.5 km/hr
25.
An alloy (X) of gold and silver is taken in the ratio 1 : 2 and another alloy (Y) of gold and silver is taken in the ratio 2 : 3. How many parts of X and Y must be taken to obtain a new alloy Z consisting of gold and silver in the ratio 4 : 7?
A.
5 : 6
B.
2 : 1
C.
3 : 5
D.
6 : 5
ANSWER :
D. 6 : 5
26.
N is a 3-digit number. The middle digit of N is equal to the sum of the other two digits and the sum of the digits is 10. How many such numbers (N) can be possible?
A.
3
B.
4
C.
5
D.
6
ANSWER :
C. 5
27.
The ratio of the cost price of two articles X and Y is 1 : 2. A businessman earns a profit of p% by selling X and a loss of 3p% by selling Y. If he loses 20% in this transaction, then what is the value of p?
A.
6%
B.
8%
C.
10%
D.
12%
ANSWER :
D. 12%
28.
A sum of money at the rate of 5% per annum compounded annually becomes n times in 100 years. What is the value of n?
(Given \( \log_{10} 2 = 0.301 \), \( \log_{10} 3 = 0.477 \) and \( \log_{10} 7 = 0.845 \))
A.
98
B.
99
C.
100
D.
More than 100
ANSWER :
D. More than 100
29.
A variable y is directly proportional to a variable quantity \( x^{n} \). Given that when x = 2, y = 20.8 and when x = 3, y = 105.3. Which one of the following is the constant of proportionality if it is greater than 1?
A.
1.1
B.
1.3
C.
2
D.
4
ANSWER :
B. 1.3
30.
If \( x = 3 - 3^{\frac{1}{3}} - 3^{\frac{2}{3}} \), then what is x(x - 3)(x - 6) equal to?
A.
-12
B.
-9
C.
0
D.
12
ANSWER :
A. -12