CDS Exam (I)- 2022 - Elementary Mathematics Defence Question Paper

CDS Previous Year Question Papers Question Papers
CDS Exam (I)- 2022 - Elementary Mathematics

CDS Exam (I)- 2022 - Elementary Mathematics Defence Questions

31.
If \( \alpha \) and \( \beta \) are the roots of the quadratic equation \( x^{2} + \alpha x + \beta = 0 \), where \( \beta \neq 0 \), then what is the value of \( \alpha - \beta \)?
A.
4
B.
3
C.
-1
D.
-3
ANSWER :
B. 3
32.
A shopkeeper marks the price of an article at ₹200. After allowing a discount of 10%, he still gains 20% on the cost price. What is the cost price of the article?
A.
₹170
B.
₹160
C.
₹150
D.
₹120
ANSWER :
C. ₹150
33.
A person borrowed ₹9,000 at 7%, ₹12,000 at 8% and ₹15,000 at 9% simple interest per annum. He had to pay ₹50,700 at the end of n years. What is the value of n?
A.
3
B.
4
C.
5
D.
6
ANSWER :
C. 5
34.
Consider the following statements:
1. The sum of the cubes of three consecutive natural numbers is divisible by 9.
2. Every even power of every odd number \( (> 1) \) when divided by 8 gives 1 as remainder.
Which of the above statements is/are correct?
A.
1 only
B.
2 only
C.
Both 1 and 2
D.
Neither 1 nor 2
ANSWER :
C. Both 1 and 2
35.
What is the number of divisors of 1000 (excluding 1 and 1000)?
A.
12
B.
13
C.
14
D.
16
ANSWER :
C. 14
36.
If the sum of the roots of the equation \( x^{2} - k^{2}x + 30kx - 161x - 64 = 0 \) is zero, then what is the difference of the roots?
A.
15
B.
16
C.
17
D.
18
ANSWER :
B. 16
37.
A piece of cloth costs ₹10,000. If a 2 m longer piece of the same cloth is purchased for the same amount, it would cost ₹250 less per metre. What is the original length of the piece of cloth?
A.
8 m
B.
10 m
C.
12 m
D.
16 m
ANSWER :
A. 8 m
38.
What is the condition that the roots of the equation \( ax^{2} + bx + c = 0 \) are in the ratio c : 1?
A.
\( b^{2} = a(c + 1)^{2} \)
B.
\( a^{2} = b(c + 1)^{2} \)
C.
\( b^{2} = a(c - 1)^{2} \)
D.
\( ab^{2} = (c + 1)^{2} \)
ANSWER :
A. \( b^{2} = a(c + 1)^{2} \)
39.
Two sides of a triangle forming a right angle are \( 6x^{2} \) and \( (2x^{2} - 1) \). If the area of the triangle is 84 square units, then what is the perimeter of the triangle?
A.
51 units
B.
53 units
C.
56 units
D.
59 units
ANSWER :
C. 56 units
40.
A train X takes 2 hours less than a train Y to cover a distance of 192 km between two cities. Their average speeds differ by 16 km/hr. How long does the faster train take to cover the journey?
A.
3 hours
B.
4 hours
C.
5 hours
D.
6 hours
ANSWER :
B. 4 hours