CDS Exam (II)- 2017 - Elementary Mathematics Defence Question Paper

CDS Previous Year Question Papers Question Papers
CDS Exam (II)- 2017 - Elementary Mathematics

CDS Exam (II)- 2017 - Elementary Mathematics Defence Questions

41.
If 78 is divided into 3 parts which are proportional to \( 1, \frac{1}{3}, \frac{1}{6} \), then the middle part is
A.
\( \frac{28}{3} \)
B.
13
C.
\( \frac{52}{3} \)
D.
\( \frac{55}{3} \)
ANSWER :
C. \( \frac{52}{3} \)
42.
There are 350 boys in the first three standards. The ratio of the number of boys in first and second standards is 2 : 3, while that of boys in second and third standards is 4 : 5. What is the total number of boys in first and third standards?
A.
302
B.
280
C.
242
D.
230
ANSWER :
D. 230
43.
The difference between the compound interest (compounded annually) and simple interest on a sum of money deposited for 2 years at 5% per annum is ₹ 15. What is the sum of money deposited?
A.
₹ 6,000
B.
₹ 4,800
C.
₹ 3,600
D.
₹ 2,400
ANSWER :
A. ₹ 6,000
44.
When prices rise by 12%, if the expenditure is to be the same, what is the percentage of consumption to be reduced?
A.
\( 16\frac{2}{3} \)%
B.
\( 10\frac{2}{7} \)%
C.
\( 16\frac{1}{3} \)%
D.
\( 10\frac{5}{7} \)%
ANSWER :
D. \( 10\frac{5}{7} \)%
45.
A man rows down a river 18 km in 4 hours with the stream and returns in 10 hours. Consider the following statements:
1. The speed of the man against the stream is 1.8 km/hr.
2. The speed of the man in still water is 3.15 km/hr.
3. The speed of the stream is 1.35 km/hr.
Which of the above statements are correct?
A.
1 and 2 only
B.
2 and 3 only
C.
1 and 3 only
D.
1, 2 and 3
ANSWER :
D. 1, 2 and 3
46.
If a triangle has sides 5, 13 and 12 units and \( \theta \) is the acute angle of the triangle, then what is the value of \( (\sin \theta + \cos \theta) \)?
A.
\( \frac{5}{13} \)
B.
\( \frac{7}{13} \)
C.
\( \frac{12}{13} \)
D.
\( \frac{17}{13} \)
ANSWER :
D. \( \frac{17}{13} \)
47.
If \( 0 < x < \frac{\pi}{2} \), then \( (\sin x + \mathrm{cosec} x) \) is
A.
= 2
B.
< 2
C.
> 2
D.
\( \leq 2 \)
ANSWER :
C. > 2
48.
If \( \sin \theta = \frac{m^{2} - n^{2}}{m^{2} + n^{2}} \) and \( 0 < \theta < \frac{\pi}{2} \), then what is the value of \( \cos \theta \)?
A.
\( \frac{2mn}{m^{2} + n^{2}} \)
B.
\( \frac{2mn}{m^{2} - n^{2}} \)
C.
\( \frac{m^{2} + n^{2}}{2mn} \)
D.
\( \frac{m^{2} - n^{2}}{2mn} \)
ANSWER :
A. \( \frac{2mn}{m^{2} + n^{2}} \)
49.
If angle A of triangle ABC is \( 30^{\circ} \) and the circum-radius of the triangle is 10 cm, then what is the length of side BC?
A.
5 cm
B.
10 cm
C.
\( 5\sqrt{3} \) cm
D.
\( 10\sqrt{3} \) cm
ANSWER :
B. 10 cm
50.
If \( A = \frac{\sin 45^{\circ} - \sin 30^{\circ}}{\cos 45^{\circ} + \cos 60^{\circ}} \) and \( B = \frac{\sec 45^{\circ} - \tan 45^{\circ}}{\mathrm{cosec} 45^{\circ} + \cot 45^{\circ}} \), then which one of the following is correct?
A.
A = B
B.
A > B > 0
C.
A < B
D.
B < A < 0
ANSWER :
A. A = B