Infotech Placement Paper
Infotech Aptitude Test
1. If 6 men and 8 boys can do a piece of work in 10 days while 26 men and 48 boys can do the same in 2 days, the time taken by 15 men and 20 boys in doing the same type of work will be:
A. 4 days
B. 5 days
C. 6 days
D. 7 days
Explanation:
Let 1 man's 1 day's work = x and 1 boy's 1 day's work = y.
Then, 6x + 8y = 1/10 and 26x + 48y = 1/2.
Solving these two equations, we get: x = 1/100 and y = 1/100.
(15 men + 20 boy)'s 1 day's work = (15/100 + 20/200) = 1/4.
.'. 15 men and 20 boys can do the work in 4 days.
2. The ratio between the speeds of two trains is 7: 8. If the second train runs 400 km in 4 hours, then the speed of the first train is:
A. 70 km/hr.
B. 75 km/hr.
C. 84 km/hr.
D. 87.5 km/hr.
Explanation:
Let the speed of two trains be 7x and 8x km/hr.
Then, 8x = (400/4) = 100.
=>x = 100 = 12.5
.'. Speed of first train = (7 x 12.5) km/hr. = 87.5 km/hr.
3. A takes twice as much time as B or thrice as much time as C to finish a piece of work. Working together, they can finish the work in 2 days. B can do the work alone in:
A. 4 days
B. 6 days
C. 8 days
D. 12 days
Explanation:
Suppose A, B and C take x, x/2 and x/3 days respectively to finish the work.
Then, (1/x + 2/x + 3/x) = 1/2.
=> 6/x = 1/2.
=> x = 12.
So, B takes (12/2) = 6 days to finish the work.
4. The average weight of A, B and C is 45 kg. If the average weight of A and B be 40 kg and that of B and C be 43 kg, then the weight of B is:
A. 17 kg
B. 20 kg
C. 26 kg
D. 31 kg
Explanation:
Let A, B, C represent their respective weights.
Then, we have:
A + B + C = (45 x 3) = 135 .... (i)
A + B = (40 x 2) = 80 .... (ii)
B + C = (43 x 2) = 86 .... (iii)
Adding (ii) and (iii), we get: A + 2B + C = 166 .... (iv)
Subtracting (i) from (iv), we get: B = 31.
=> B's weight = 31 kg.
5. Sam purchased 20 dozens of toys at the rate of Rs. 375 per dozen. He sold each one of them at the rate of Rs. 33. What was his percentage profit?
A. 3.5
B. 4.5
C. 5.6
D. 6.5
Explanation:
Cost Price of 1 toy = Rs.375/12 = Rs. 31.25.
Selling Price of 1 toy = Rs. 33
So, Gain = Rs. (33 - 31.25) = Rs. 1.75
Profit % = (1.75/31.25 x 100) % = 28/5% = 5.6%.
6. A number consists of two digits. If the digit's interchange places and the new number is added to the original number, then the resulting number will be divisible by:
A. 3
B. 5
C. 9
D. 11
Explanation:
Let the ten's digit be x and unit's digit be y.
Then, number = 10x + y.
Number obtained by interchanging the digits = 10y + x.
=> (10x + y) + (10y + x) = 11(x + y), which is divisible by 11.
7. A boat covers a certain distance downstream in 1 hour, while it comes back in 1 hours. If the speed of the stream be 3 kmph, what is the speed of the boat in still water?
A. 12 kmph
B. 13 kmph
C. 14 kmph
D. 15 kmph
E. None of these
Explanation:
Let the speed of the boat in still water be x kmph. Then,
Speed downstream = (x + 3) kmph,
Speed upstream = (x - 3) kmph.
.'. (x + 3) x 1 = (x - 3) x 3/2
=> 2x + 6 = 3x - 9
=> x = 15 kmph.
8. The sum of three numbers is 98. If the ratio of the first to second is 2 :3 and that of the second to the third is 5: 8, then the second number is:
A. 20
B. 30
C. 48
D. 58
Explanation:
Let the three parts be A, B, C. Then,
A: B = 2: 3 and B: C = 5: 8
=> (5 x 3/5): (8 x 3/5) = 3: 24/5
=> A: B: C = 2: 3: 24/5 = 10: 15: 24
=> B = 98 x 15/49 = 30.
9. A rectangular field is to be fenced on three sides leaving a side of 20 feet uncovered. If the area of the field is 680 sq. feet, how many feet of fencing will be required?
A. 34
B. 40
C. 68
D. 88
Explanation:
We have: l = 20 ft and lb = 680 sq. ft.
So, b = 34 ft.
Length of fencing = (l + 2b) = (20 + 68) ft = 88 ft.
10. A tank is filled by three pipes with uniform flow. The first two pipes operating simultaneously fill the tank in the same time during which the tank is filled by the third pipe alone. The second pipe fills the tank 5 hours faster than the first pipe and 4 hours slower than the third pipe. The time required by the first pipe is:
A. 6 hours
B. 10 hours
C. 15 hours
D. 30 hours
Explanation:
Suppose, first pipe alone takes x hours to fill the tank.
Then, second and third pipes will take (x -5) and (x - 9) hours respectively to fill the tank.
.'. 1/x + 1/(x-5) = 1/(x-9).
=> (x - 5 + x)/x(x-5) = 1/(x-9).
=> (2x - 5) (x - 9) = x (x - 5).
=> x^2 - 18x + 45 = 0.
=> (x - 15) (x - 3) = 0.
=> x = 15. [neglecting x = 3]
11. The average age of a family of four members is 25 years. If the age of the youngest member be 15 years, then what was the average age of the family at the time of the birth of the youngest member?
A. 13.5
B. 14
C. 15
D. 13.33
Explanation:
At present the total age of the family = 4 * 25 = 100.
The total age of the family at the time of the birth of the youngest member = [100-15-(15*3)] =40.
Therefore, average age of the family at the time of birth of the youngest member = 40/3 = 13.33.
12. Two different numbers are divided by the same divisor and left remainder 11 and 17 respectively and when their sum was divided by the same divisor, remainder was 4. What is the divisor?
A. 20
B. 24
C. 25
D. 26
E. 28
F. None of these
Explanation:
Let the divisor = D
So, first number = D*a + 11 and second number = D*b +17
Thus, sum of numbers = D*(a + b) + 28
Given that remainder is 4 so, the number is 24.
13. If the length of the rectangle is increased by 20%, by what percent should the width be reduced to maintain the same area?
A. 13.37
B. 16.67
C. 21.33
D. 33.33
E. None of these
Explanation:
Let length = 100 and breadth = 100.
Now, new length = 120 and let breadth = b.
So, 100*100 = 120*b.
=> b = 250/3.
So, % decrease = 100 “ 250/3 = 50/3 = 16.67%.
14. The population of a town is 15000. It increases by 10 percent in the first year and 20 percent in the second year. But in the third year it decreases by 10 percent. What will be the population after 3 years?
A. 16820
B. 15820
C. 17820
D. 19820
E. None of these
Explanation:
The Population after 3 years will be:
=> 15000 * (11/10) * (12/10) * (9/10) = 17820.
15. Three friends Alice, Bond and Charlie divide Rs. 1105 amongst them in such a way that if Rs. 10, Rs. 20 and Rs. 15 are removed from the sums that Alice, Bond and Charlie received respectively, then the share of the sums that they got will be in the ratio of 11: 18: 24. How much did Charlie receive?
A. Rs. 495
B. Rs. 510
C. Rs. 480
D. Rs. 375
E. Rs. 360
Explanation:
Let the sums of money received by A, B and C be x, y and z respectively.
Then x - 10: y - 20: z -15 is 11a: 18a: 24a
When Rs. 10, Rs. 20 and Rs. 15 are removed, we are removing a total of Rs. 45 from Rs. 1105.
Therefore, 11a + 18a + 24a = 1105 - 45 = 1060
=> 53a = 1060
=> a = 20.
We know that z - 15 = 24a = 24 * 20 = 480.
Therefore, z = 480 + 15 = Rs. 495.
16. The ratio of the outer and the inner perimeters of a circular path is 9: 8. The path is 3 meters wide. What is the diameter of the outer circle?
A. 20 m
B. 27 m
C. 35 m
D. 39 m
E. 24 m
Explanation:
Let the outer and the inner perimeters of a circular path be 2á´¨r and 2á´¨R respectively.
According to the question,
=> 2á´¨r/2á´¨R = 9/8
So, r/R = 9/8, so r = (9/8) R
=> r-R = 3, so (9/8) R “ R = 3
=> R = 24, so r = (9/8) *24 = 27
17. A walks with a speed of 6 km/hr. and after 5 hr. of his start, B starts running towards A at a speed of 8 km/hr. At what distance from start will B catch A?
A. 100 km
B. 110 km
C. 120 km
D. 140 km
E. None of these
Explanation:
In 5hrs, A will cover 30 km. Now, at some distance 'x'. So A will cover X distance and B will cover 30 + X.
=> x/6 = (30+x)/8
=> x = 90.
So, distance from start after which B will catch A = 120km.
18. A man can row at 4 kmph in still water. If the velocity of the current is 1 kmph and it takes him 1 hour to row to a place and come back. How far is that place?
A. 1.8 km
B. 2.6 km
C. 1.5 km
D. 3.2 km
E. None of these
Explanation:
Let the distance is x km
Rate downstream = 4 + 1 = 5 kmph
Rate upstream = 4 “ 1 = 3 kmph
Then,
=> x/5 + x/3 = 1.
=> 3x + 5x = 15.
=> x = 15/8 = 1.8 km.
19. The marked price of a watch was Rs. 720.A man brought the same for Rs.550.80 after getting two successive discounts the first being 10%. What was the second discount rate?
A. 12%
B. 14%
C. 15%
D. 18%
Explanation:
Let the second discount rate be x% Then,
=> (100 “ x) % of 90% of 720 = 550.80
=> (100 “ x)/100 x 90/100 x 720 = 550.80
=> (100-x) = [55080/ (9 x 72) = 85
=> x= 15
Hence, the second discount rate =15%.
20. The length and breadth of a rectangular field are in the ratio 3:2. If the perimeter of the field is 80 m, its breadth (in meters) is-
A. 18 m
B. 16 m
C. 10 m
D. 24 m
Explanation:
Let length and breadth be 3x and 2x respectively.
Perimeter = 2(l+b)
=> 2(3x+2x) = 10x.
Given, Perimeter = 80.
So, 10x = 80.
=> x = 8.
Therefore, the breadth of the field = 8 * 2 i.e. 16 m.
Infotech Technical Test
21. The number of tuples in a relation is called its_________ While the number of attributes in a relation is called it's ___________.
A. Degree, Cardinality
B. Cardinality, Degree
C. Rows, Columns
D. Columns, Rows
Answer: B.
22. Which of the following is not the required condition for binary search algorithm?
A. The list must be sorted
B. there should be the direct access to the middle element in any sublist
C. There must be mechanism to delete and/or insert elements in list
D. none of above
Answer: C.
23. What will be the output of the following program on GCC compiler?
#include
int main() {
int x=12, y=7, z;
z = x!=4 || y == 2;
printf("z=%d\n", z);
return 0;
}
A. z=0
B. z=1
C. z=2
D. z=4
Explanation:
In the statement " z = (x! =4) || (y == 2)", x! =4 evaluates to true.
Since, the first condition of || returns 'true', other side of || doesn't get tested.
Thus, 'true' value of first condition i.e. 1 gets stored in z.
24. Which of the following is correct about the statements given below?
(I) All operators can be overloaded in C++.
(II) We can change the basic meaning of an operator in C++.
A. Only I is true.
B. Both I and II are false.
C. Only II is true.
D. Both I and II are true.
Answer: B.
25. Which of the following is not a consequence of non-normalized database?
A. Update Anomaly
B. Insertion Anomaly
C. Redundancy
D. Lost update problem
Answer: D.
Like this ?
+ 1
- 0
