Wrong questions in apti

1.

The least perfect square, which is divisible by each of 21, 36 and 66 is:
A. 213444

B. 214344

C. 214434

D. 231444
Your Answer: Option A
Correct Answer: Option A
Explanation:
L.C.M. of 21, 36, 66 = 2772.
Now, 2772 = 2 x 2 x 3 x 3 x 7 x 11
To make it a perfect square, it must be multiplied by 7 x 11.
So, required number = 22 x 32 x 72 x 112 = 213444
Learn more problems on : Square Root and Cube Root

One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill the tank in 36
minutes, then the slower pipe alone will be able to fill the tank in:
A. 81 min.

B. 108 min.

C. 144 min.

D. 192 min.
Your Answer: Option B
Correct Answer: Option C
Explanation:
Let the slower pipe alone fill the tank in x minutes.
x
Then, faster pipe will fill it in minutes.
3
1 3 1
+ =
x x 36
4 1
=
x 36
x = 144 min.
A motorboat, whose speed in 15 km/hr in still water goes 30 km downstream and comes back in a total of 4
hours 30 minutes. The speed of the stream (in km/hr) is:
A. 4

B. 5

C. 6

D. 10
Your Answer: Option B
Correct Answer: Option B
Explanation:
Let the speed of the stream be x km/hr. Then,
Speed downstream = (15 + x) km/hr,
Speed upstream = (15 - x) km/hr.
30 30 1
+ =4
(15 + x) (15 - x) 2
900 9
=
225 - x2 2
9x2 = 225
x2 = 25
x = 5 km/hr.

A man walked diagonally across a square lot. Approximately, what was the percent saved by not walking
along the edges?
A. 20

B. 24

C. 30

D. 33
Your Answer: Option C
Correct Answer: Option C
Explanation:
Let the side of the square(ABCD) be x metres.

Then, AB + BC = 2x metres.
AC = 2x = (1.41x) m.
Saving on 2x metres = (0.59x) m.
Saving % = 0.59x x 100 = 30% (approx.)
%
 2x

By investing in 16 % stock at 64, one earns Rs. 1500. The investment made is:
A. Rs. 5640

B. Rs. 5760

C. Rs. 7500

D. Rs. 9600
Your Answer: Option B
Correct Answer: Option B
Explanation:
50
To earn Rs. , investment = Rs. 64.
3
3
To earn Rs. 1500, investment = Rs. 64 x x 1500 = Rs. 5760.
50

A man buys a watch for Rs. 1950 in cash and sells it for Rs. 2200 at a credit of 1 year. If the rate of interest is
10% per annum, the man:
A. gains Rs. 55

B. gains Rs. 50

C. loses Rs. 30

D. gains Rs. 30
Your Answer: Option D
Correct Answer: Option B
Explanation:
S.P. = P.W. of Rs. 2200 due 1 year hence

2200 x 100
= Rs.
100 + (10 x 1)

= Rs. 2000.

Gain = Rs. (2000 - 1950) = Rs. 50.

Learn more problems on : True Discount
A, B and C can do a piece of work in 20, 30 and 60 days respectively. In how many days can A do the work if
he is assisted by B and C on every third day?
A. 12 days

B. 15 days

C. 16 days

D. 18 days
Your Answer: Option B
Correct Answer: Option B
Explanation:
1 1
A's 2 day's work = x2 = .
20 10
1 1 1 6 1
(A + B + C)'s 1 day's work = + + = = .
20 30 60 60 10
1 1 1
Work done in 3 days = + = .
10 10 5
1
Now, work is done in 3 days.
5
Whole work will be done in (3 x 5) = 15 days.

Robert is travelling on his cycle and has calculated to reach point A at 2 P.M. if he travels at 10 kmph, he will
reach there at 12 noon if he travels at 15 kmph. At what speed must he travel to reach A at 1 P.M.?
A. 8 kmph

B. 11 kmph

C. 12 kmph

D. 14 kmph
Your Answer: Option C
Correct Answer: Option C
Explanation:
Let the distance travelled by x km.
x x
Then, - =2
10 15
3x - 2x = 60
x = 60 km.
60
Time taken to travel 60 km at 10 km/hr = = 6 hrs.
10 hrs
So, Robert started 6 hours before 2 P.M. i.e., at 8 A.M.
60
Required speed = = 12 kmph.
5 kmph.

A man rows to a place 48 km distant and come back in 14 hours. He finds that he can row 4 km with the
stream in the same time as 3 km against the stream. The rate of the stream is:
A. 1 km/hr

B. 1.5 km/hr

C. 2 km/hr

D. 2.5 km/hr
Your Answer: Option B
Correct Answer: Option A
Explanation:
Suppose he move 4 km downstream in x hours. Then,
4
Speed downstream = km/hr.
x
3
Speed upstream = km/hr.
x
48 48 1
+ = 14 or x = .
(4/x) (3/x) 2
So, Speed downstream = 8 km/hr, Speed upstream = 6 km/hr.
1
Rate of the stream = (8 - 6) km/hr = 1 km/hr.
2

In what ratio must a grocer mix two varieties of pulses costing Rs. 15 and Rs. 20 per kg respectively so as to
get a mixture worth Rs. 16.50 kg?
A. 3:7

B. 5:7
 C. 7 : 3

D. 7 : 5
Your Answer: Option B
Correct Answer: Option C
Explanation:
By the rule of alligation:

Cost of 1 kg pulses of 1st kindCost of 1 kg pulses of 2nd kind

Rs. 15 Mean Price Rs. 20
3.50 Rs. 16.50 1.50

Required rate = 3.50 : 1.50 = 7 : 3.

In a race of 200 m, A can beat B by 31 m and C by 18 m. In a race of 350 m, C will beat B by:
A. 22.75 m

B. 25 m

C. 19.5 m

4
D. 7 m
7
Your Answer: Option D
Correct Answer: Option B
Explanation:
A : B = 200 : 169.
A : C = 200 : 182.
C C A 182 200
= x = x = 182 : 169.
B A B 200 169
When C covers 182 m, B covers 169 m.
169
When C covers 350 m, B covers x 350 = 325 m.
182 m
Therefore, C beats B by (350 - 325) m = 25 m.
From a pack of 52 cards, two cards are drawn together at random. What is the probability of both the cards
being kings?
1
A.
15

25
B.
57

35
C.
256

1
D.
221

Your Answer: Option B

Correct Answer: Option D
Explanation:
Let S be the sample space.
(52 x 51)
Then, n(S) = C2 =
52
= 1326.
(2 x 1)

Let E = event of getting 2 kings out of 4.

(4 x 3)
n(E) = 4C2 = = 6.
(2 x 1)

n(E) 6 1
P(E) = = = .
n(S) 1326 221

Learn more problems on : Probability

22, 33, 66, 99, 121, 279, 594

A. 33
 B. 121

C. 279

D. 594
Your Answer: Option B
Correct Answer: Option C
Explanation:
Each of the number except 279 is a multiple of 11.

3. What was the day of the week on 28th May, 2006?

A. Thursday

B. Friday

C. Saturday

D. Sunday

Your Answer: Option D

Correct Answer: Option D
Explanation:
28 May, 2006 = (2005 years + Period from 1.1.2006 to 28.5.2006)
Odd days in 1600 years = 0
Odd days in 400 years = 0
5 years = (4 ordinary years + 1 leap year) = (4 x 1 + 1 x 2) 6 odd days

Jan. Feb. March April May

(31 + 28 + 31 + 30 + 28 ) = 148 days
148 days = (21 weeks + 1 day) 1 odd day.
Total number of odd days = (0 + 0 + 6 + 1) = 7 0 odd day.
Given day is Sunday.
Learn more problems on : Calendar
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14. The angle between the minute hand and the hour hand of a clock when the time is 4.20, is:
A. 0
 B. 10

C. 5

D. 20

Your Answer: Option A

Correct Answer: Option B
Explanation:
13 360 13
Angle traced by hour hand in hrs = x = 130.
3 12 3

360
Angle traced by min. hand in 20 min. = x 20 = 120.
60

Required angle = (130 - 120) = 10.

Learn more problems on : Clock
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15. At what angle the hands of a clock are inclined at 15 minutes past 5?
1
A. 58
2

B. 64

1
C. 67
2

1
D. 72
2

Your Answer: Option B

Correct Answer: Option C
Explanation:
21 360 21 1
Angle traced by hour hand in hrs = x = 157
4 12 4 2
 360
Angle traced by min. hand in 15 min. = x 15 = 90.
60

1 1
Required angle = 157 - 90 = 67
2 2

Learn more problems on : Clock

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16. The angle between the minute hand and the hour hand of a clock when the time is 8.30, is:
A. 80

B. 75

C. 60

D. 105

Your Answer: Option C

Correct Answer: Option B
Explanation:
17 360 17
Angle traced by hour hand in hrs = x = 255.
2 12 2

360
Angle traced by min. hand in 30 min. = x 30 = 180.
60

Required angle = (255 - 180) = 75.

Learn more problems on : Clock
Discuss about this problem : Discuss in Forum
17. At what time between 9 and 10 o'clock will the hands of a watch be together?
A. 45 min. past 9

B. 50 min. past 9

1
C. 49 min. past 9
11
 2
D. 48 min. past 9
11

Your Answer: Option B

Correct Answer: Option C
Explanation:
To be together between 9 and 10 o'clock, the minute hand has to gain 45 min. spaces.
55 min. spaces gained in 60 min.
60 1
45 min. spaces are gained in x 45 min.
55 min or 4911

1
The hands are together at 49 min. past 9.
11

Learn more problems on : Clock

A person takes a loan of Rs. 200 at 5% simple interest. He returns Rs. 100 at the end of 1 year. In order to clear
his dues at the end of 2 years, he would pay:
A. Rs. 105

B. Rs. 110

C. Rs. 115

D. Rs. 115.50

Your Answer: Option B

Correct Answer: Option C
Explanation:
200 x 5 x 1 100 x 5 x 1
Amount to be paid = Rs. 100 + +
100 100

= Rs. 115.

Learn more problems on : Simple Interest

1
If x = 3 + 22, then the value of x - is:
x
 A. 1

B. 2

C. 22

D. 33

Your Answer: Option A

Correct Answer: Option B
Explanation:
1 2 1
x - =x+ -2
x x

1
= (3 + 22) + -2
(3 + 22)

1 (3 - 22)
= (3 + 22) + x -2
(3 + 22) (3 - 22)

= (3 + 22) + (3 - 22) - 2
= 4.
1
x - = 2.
x

Learn more problems on : Surds and Indices

If the sum of two numbers is 55 and the H.C.F. and L.C.M. of these numbers are 5 and 120
respectively, then the sum of the reciprocals of the numbers is equal to:
55
A.
601

601
B.
55
 11
C.
120

120
D.
11

Your Answer: Option C

Correct Answer: Option C
Explanation:
Let the numbers be a and b.
Then, a + b = 55 and ab = 5 x 120 = 600.
1 1 a+b 55 11
The required sum = + = = =
a b ab 600 120

Learn more problems on : Problems on H.C.F and L.C.M

If a = 0.1039, then the value of 4a2 - 4a + 1 + 3a is:

A. 0.1039

B. 0.2078

C. 1.1039

D. 2.1039

Your Answer: Option B

Correct Answer: Option C
Explanation:
4a2 - 4a + 1 + 3a = (1)2 + (2a)2 - 2 x 1 x 2a + 3a
= (1 - 2a)2 + 3a
= (1 - 2a) + 3a
= (1 + a)
= (1 + 0.1039)
= 1.1039
Learn more problems on : Square Root and Cube Root

The product of two numbers is 9375 and the quotient, when the larger one is divided by the smaller,
is 15. The sum of the numbers is:
 A. 380

B. 395

C. 400

D. 425

Your Answer: Option C

Correct Answer: Option C
Explanation:
Let the numbers be x and y.
x
Then, xy = 9375 and = 15.
y

xy 9375
=
(x/y) 15

y2 = 625.
y = 25.
x = 15y = (15 x 25) = 375.
Sum of the numbers = x + y = 375 + 25 = 400.
Learn more problems on : Problems on Numbers

What is the two-digit number?

I. The difference between the two-digit number and the number formed by interchanging the digits
is 27.

II. The difference between the two digits is 3.

III. The digit at unit's place is less than that at ten's place by 3.

A. I and II only

B. I and III only

C. All I, II and III

 D. I, and either II or III

E. Even with all I, II and III, answer cannot be give.

Your Answer: Option D

Correct Answer: Option E
Explanation:
Let the tens and units digit be x and y respectively.
I. (10x + y) - (10y + x) x - y = 3.
II. x - y = 3.
III. x - y = 3.
Thus, even all the given three statements together do not give the answer.
Correct answer is (E).
Learn more problems on : Problems on Numbers

Some articles were bought at 6 articles for Rs. 5 and sold at 5 articles for Rs. 6. Gain percent is:
A. 30%

1
B. 33 %
3

C. 35%

D. 44%

Your Answer: Option B

Correct Answer: Option D
Explanation:
Suppose, number of articles bought = L.C.M. of 6 and 5 = 30.
5
C.P. of 30 articles = Rs. x 30 = Rs. 25.
6

6
S.P. of 30 articles = Rs. x 30 = Rs. 36.
5

Gain % = 11 x 100
% = 44%.
 25

Learn more problems on : Profit and Loss

At what time will the train reach city X from city Y?

I. The train crosses another train of equal length of 200 metres and running in opposite directions
in 15 seconds.

II. The train leaves city Y and 7.15 a.m. for city X situated at a distance of 558 km.

III. The 200 metres long train crosses a signal pole in 10 seconds.

A. I only

B. II only

C. III only

D. II and III only

E. All I, II and III are required.

Your Answer: Option B

Correct Answer: Option D
Explanation:
From the statement I, we get length of the train is 200 metres (Redundant info while comparing with
Statement III). The rest of the info given in this statement cannot be used for calculating the speed of
the train, because the two trains might run at different speed.
200 18
III gives, speed = m/sec = 20 m/sec = 20 x
10 5 km/hr = 72 km/hr.

558 31 3
II gives, time taken = hrs = 7 hrs = 7 hrs 45 min.
72 hrs = 4 4

So, the train will reach city X at 3 p.m.

Hence II and III only gives the answer.
Learn more problems on : Problems on Trains
What is the speed of the boat in still water?

I. The speed downstream is 12 kmph.

II. The speed upstream is 4 kmph.

III. In a to and fro journey between two points, the average speed of the boat was 6 kmph.

A. I and II only

B. All I, II and III

C. III, and either I or II

D. Any two of the three

E. None of these

Your Answer: Option C

Correct Answer: Option D
Explanation:
1
From I and II, speed of boat in still water = (12 + 4) km/hr = 8 km/hr.
2

From II and III, we get:

2xy 2x4xy
Using average speed = , we get: =6
x+y 4+y

8y = 24 + 6y
y = 12.
1
Required speed = (12 + 4) km/hr = 8 km/hr.
2

Similarly, I and III also give the answer.

Correct answer is (D).
Learn more problems on : Boats and Streams