CDS Exam (I)- 2018 - Elementary Mathematics Defence Question Paper

CDS Previous Year Question Papers Question Papers
CDS Exam (I)- 2018 - Elementary Mathematics

CDS Exam (I)- 2018 - Elementary Mathematics Defence Questions

41.
All odd prime numbers upto 110 are multiplied together. What is the unit digit in this product?
A.
0
B.
3
C.
5
D.
None of the above
šŸ˜‘ View Answer Error
ANSWER :
C. 5
42.
An alloy A contains two elements, copper and tin in the ratio of 2 : 3, whereas an alloy B contains the same elements in the ratio of 3 : 4. If 20 kg of alloy A, 28 kg of alloy B and some more pure copper are mixed to form a third alloy C which now contains copper and tin in the ratio of 6 : 7, then what is the quantity of pure copper mixed in the alloy C?
A.
3 kg
B.
4 kg
C.
5 kg
D.
7 kg
šŸ˜‘ View Answer Error
ANSWER :
B. 4 kg
43.
A quadratic polynomial \( ax^{2} + bx + c \) is such that when it is divided by x, (x āˆ’ 1) and (x + 1), the remainders are 3, 6 and 4 respectively. What is the value of (a + b)?
A.
3
B.
2
C.
1
D.
āˆ’1
šŸ˜‘ View Answer Error
ANSWER :
A. 3
44.
If the average of 9 consecutive positive integers is 55, then what is the largest integer?
A.
57
B.
58
C.
59
D.
60
šŸ˜‘ View Answer Error
ANSWER :
C. 59
45.
The average of the ages of 15 students in a class is 19 years. When 5 new students are admitted to the class, the average age of the class becomes 18.5 years. What is the average age of the 5 newly admitted students?
A.
17 years
B.
17.5 years
C.
18 years
D.
18.5 years
šŸ˜‘ View Answer Error
ANSWER :
A. 17 years
46.
A man can row at a speed of x km/hr in still water. If in a stream which is flowing at a speed of y km/hr it takes him z hours to row to a place and back, then what is the distance between the two places?
A.
\( \frac{z(x^{2}-y^{2})}{2y} \)
B.
\( \frac{z(x^{2}-y^{2})}{2x} \)
C.
\( \frac{x^{2}-y^{2}}{2zx} \)
D.
\( \frac{z(x^{2}-y^{2})}{x} \)
šŸ˜‘ View Answer Error
ANSWER :
B. \( \frac{z(x^{2}-y^{2})}{2x} \)
47.
A water tank has been fitted with two taps P and Q and a drain pipe R. Taps P and Q fill at the rate of 12 litres per minute and 10 litres per minute respectively.
Consider the following statements S1, S2 and S3:
S1: Pipe R drains out at the rate of 6 litres per minute.
S2: If both the taps and the drain pipe are opened simultaneously, then the tank is filled in 5 hours 45 minutes.
S3: Pipe R drains out (fully) the filled tank in 15 hours 20 minutes.
To know what is the capacity of the tank, which one of the following is correct?
A.
S2 is only sufficient
B.
S1, S2 and S3 are necessary
C.
Any two out of S1, S2 and S3 are sufficient
D.
None of the above
šŸ˜‘ View Answer Error
ANSWER :
C. Any two out of S1, S2 and S3 are sufficient
48.
A car has an average speed of 60 km per hour while going from Delhi to Agra and has an average speed of y km per hour while returning to Delhi from Agra (by travelling the same distance). If the average speed of the car for the whole journey is 48 km per hour, then what is the value of y?
A.
30 km per hour
B.
35 km per hour
C.
40 km per hour
D.
45 km per hour
šŸ˜‘ View Answer Error
ANSWER :
C. 40 km per hour
49.
An article is sold at a profit of 32%. If the cost price is increased by 20% and the sale price remains the same, then the profit percentage becomes
A.
10%
B.
12%
C.
15%
D.
20%
šŸ˜‘ View Answer Error
ANSWER :
A. 10%
50.
A, B, C, D and E start a partnership firm. Capital contributed by A is three times that contributed by D. E contributes half of Aā€™s contribution, B contributes one-third of Eā€™s contribution and C contributes two-third of Aā€™s contribution. If the difference between the combined shares of A, D and E and the combined shares of B and C in the total profit of the firm is ā‚¹ 13,500, what is the combined share of B, C and E? (The shares are supposed to be proportional to the contributions)
A.
ā‚¹ 13,500
B.
ā‚¹ 18,000
C.
ā‚¹ 19,750
D.
ā‚¹ 20,250
šŸ˜‘ View Answer Error
ANSWER :
B. ā‚¹ 18,000
Prev Next page