ARITHMETIC ABILITY 5

Thursday, April 29, 2010

Read the questions carefully and pick the correct answer.


1.
A man 2.8 meters tall casts a shadow 2.4 metres long and at the same time a building to him casts a shadow 10.8 meters long. What is the height of the building?
A.
12.6 m

B.
14.5 m
C.
16 m
D.
20 m
Answer & Explanation
Answer: Option A
Explanation:
Let the height Of the building be h metres2.8/2.4 = h/10.8h = 2.8 x 10.8 / 2.4 = 12.6 meters

2.
If 40 men can build a wall 224 metres long in 12 days what length of wall can be built by 50men in 6 days
A.
140 m

B.
120 m
C.
160 m
D.
200 m
Answer & Explanation
Answer: Option A
Explanation:
M1 T1 / W1 = M2 T2 / W240 X 12 / 224 = 50 X 6 / X \ X = 140length of wall built = 140 metres

3.
If 34 men can dig a ditch 52 m long in 36 days working 16 hours a day, how many more men should be engaged to dig a similar ditch 78 m long in 12 days, each man now working 18 hours a day.
A.
102

B.
200
C.
35
D.
78
Answer & Explanation
Answer: Option A
Explanation:
M1 = 34, R1 = 161 T1 = 361 W1 = 521 M2 =21 R2 =181T2 = 12 1 W2 = 78(34 x 16 x 35) / 52 = (M2 x 18 x 12) / 7819584 / 52 = 216 M 2 / 781123 M 2 = 1527552M 2 = 136No. of extra men to be employed= 136 - 34 = 102

4.
Two balls have their radii in the ratio 2:6 what is the ratio of their volumes ?
A.
1:27

B.
2:30
C.
1:3
D.
2:1
Answer & Explanation
Answer: Option A
Explanation:
V1 : V2 = (R 3)3 : (R 2)3= 23 : 63= 8 : 216= 1 : 27

5.
The parameters of x and y of an object are such that x = 18 / 286y 2 Two such similar objects of different sizes have their parameter y in the ratio 4:6 what is the ratio of the parameters x
A.
9:4

B.
8:3
C.
2:3
D.
3:1
Answer & Explanation
Answer: Option A
Explanation:
X1 : X2 = 1 / Y12 : 1 / Y22= 1 / 16 : 1/ 36X1 : X2 = 36 : 16 = 9 : 4

6.
X earns 25% more than y by how much percent is y's income less than that of x
A.
20%

B.
30%
C.
25%
D.
5%
Answer & Explanation
Answer: Option A
Explanation:
Let y's income be Rs.100.Then X's income = Rs.125
X
Y
125
100
100
?= 100 x 100 / 125 = 80Y's Income is 20% less than x.

7.
In an exam , 40% are the passing marks. If a student gets 20marks and fails by 10 marks, what are the maximum marks.
A.
75

B.
100
C.
150
D.
25
Answer & Explanation
Answer: Option A
Explanation:
Total passing marks = 20 + 10 = 3040 % of maximum marks = 30Maximum Marks = 30 x 100 / 40 = 75

8.
In an election one of the 2 candidates gets 42% of the total votes and still loses by 368 votes. What is the total no. of votes
A.
2300

B.
2500
C.
1200
D.
1400
Answer & Explanation
Answer: Option A
Explanation:
In an election, one of the 2 candidates gets 42% of the total voted and still losesLet the total no. of votes be 100Votes secured by defeated candidate = 42Votes secured by winning candidate = 58Diff = 16= 368 x 100 / 16 = 2300

9.
Rice is now being sold at Rs. 30 kg. Last month its rate was Rs. 26 Kg. By how much % should a family reduce its consumption so as to keep the expenditure fixed.
A.
13.33%

B.
15%
C.
20%
D.
12%
Answer & Explanation
Answer: Option A
Explanation:
Let earlier consumption be 1 kgearlier expend = Rs.26Now Rs. 30 gives 1 KgRs. 26 gives 26 / 30 Kg.Reduction in consumption = 1 -26 / 30 = 4 / 30 Kg.Reduction % = 4 / 30 x 100 = 13/3 %

10.
A batsman increases his average by 4 runs when he makes 126 runs in his 12th innings. What is his average after 12 innings.
A.
82%

B.
85%
C.
75%
D.
80%
Answer & Explanation
Answer: Option A
Explanation:
Average score after 11 innings = 126 - (4 x 12)= 126 - 48 = 78Average Score after 12 innings = 78 + 4 = 82

11.
If a and b are integer and ab = 81 which of the following cannot be the value of a+b
A.
82
B.
30
C.
25

D.
18
Answer & Explanation
Answer: Option C
Explanation:
ab = 81Factor of 81 are 81,1 or 27 , 3 , or 9, 9 , Their Sum is equal to 82,30,18 But there are no factors whose sum is 25 .

12.
Tap A can fill a tank in 4 hours Because of a leak it took 5 hours to fill the tank. In how much time, the leak can drain all the water of the tank.
A.
20

B.
25
C.
22
D.
23
Answer & Explanation
Answer: Option A
Explanation:
Without Leakage (1/4) tank can be filled in 1 hours with leakage 1/5 tank can be filled in 1 hour.Leakage per hour = 1/4- /5= 1/20 Time taken to drain all the water is 20 Hours

13.
In what proportion should water be added to a liquid costing Rs.20 per liter so as to make a profit of 20% by selling the mixture at Rs. 15.
A.
2:5
B.
1:2
C.
2:3
D.
3:5

Answer & Explanation
Answer: Option D
Explanation:
Let a and b be the amount of liquid and water in the mixture(1.2) (20) a = 15 (a+b)24 a = 15a + 15b9a = 15b3a = 5bThe ratio = 3 : 5

14.
If I sell a dog for Rs.650 and a cat for Rs. 300. I gain 20% on the original cost of both but if I sell the dog for Rs.675 and the cat for its original price I lose 20%. The original cost of the cat is
A.
280
B.
275

C.
300
D.
325
Answer & Explanation
Answer: Option B
Explanation:
Let d and c be the original cost of the dog and the cat650 + 300 = 102 (d + c)675 + c = 0.8 ( d + c)950 = 1.2 d + 1.2 c0.2 c - 0.8 = - 67512d + 12 c = 950048 d -12 c = 4050060 d = 31000d = 516.67c = Rs. 275

15.
Manoj buys 100 articles on which he has to pay Rs. 20 as carriage. The articles were marked for sale at Rs.10. He sells 80 of them at this price and the remaining after allowing a discount of 10% on the marked price. At the end he finds that he has made a profit of 30% on his outlay. Find the amount he pays for each article
A.
8.22
B.
5.65
C.
7.33

D.
6
Answer & Explanation
Answer: Option C
Explanation:
Let the costprice of each article be x( 100 + 20) x 1.30 = 10 x 80 + 20 x 9130 x + 26 = 800 + 180x = Rs. 7.33

16.
At a party, first the ratio of boys to girls was 5 to 4. If 20 boys left the ratio became 1 : 1, how many people were there originally at the party.
A.
220
B.
200
C.
180

D.
150
Answer & Explanation
Answer: Option C
Explanation:
Let the number of boys and girls be b and g initallyB/g = 5/4 and b-20 /g = 1B/ b -20 = 5/44b = 5b-100b = 100and number of girls = 100-20 =80Therefore total number of people at the party = 180

17.
There are 4 picture nails and 6 different pictures. In how many different ways can pictures be hung on all nails.
A.
100
B.
360

C.
450
D.
500
Answer & Explanation
Answer: Option B
Explanation:
Required number of arrangement = 6p 4 = 61 / 21 = 360

18.
Ashok marks his goods such that he can reduce 10% for cash and yet make 20% profit what is the marked price of an article which costs Rs.120
A.
160

B.
180
C.
200
D.
150
Answer & Explanation
Answer: Option A
Explanation:
x - 10 x / 100 = 1449x = 1440x = 160

19.
In a game of cricket P's runs are to Q's runs and Q's runs are to R's runs as 4:5. The score 300 runs altogether. How many runs are scored by Q's
A.
130
B.
100

C.
150
D.
120
Answer & Explanation
Answer: Option B
Explanation:
Let P , Q and R be the respective scoresP/Q = Q/R = 4/5P = 4Q/5 AND R= 5Q/4P+Q+R = Q (4/5 + 1 + 5/4) = 305=Q (3005) = 305Q = 300

20.
In an examination 10% candidates fail in English, 15% in History and 5% in both. If 2000 candidates pass in both the subjects, Find the total number of candidates appearing in the examination.
A.
2500

B.
3000
C.
4000
D.
3500
Answer & Explanation
Answer: Option A
Explanation:
% of candidates who failed in atleast one subject = 15 + 10 -5 = 20%% passed in both = 80%80% = 2000Therefore total number of candidates = 2500