Quantitative Aptitude - Arithmetic Ability Questions

Q:

The probability of success of three students X, Y and Z in the one examination are 1/5, 1/4 and 1/3 respectively. Find the probability of success of at least two.

A) 1/4 B) 1/2
C) 1/6 D) 1/3
 
Answer & Explanation Answer: C) 1/6

Explanation:

P(X) = 15, P(Y) =14 , P(Z) = 13

 

Required probability:

 

= [ P(A)P(B){1−P(C)} ] + [ {1−P(A)}P(B)P(C) ] + [ P(A)P(C){1−P(B)} ] + P(A)P(B)P(C)

 

=14*13*45+34*13*15+23*14*15+14*13*15

 

460+360+260+160106016

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Filed Under: Probability

19 19658
Q:

In a fort, there are 1200 soldiers. If each soldier consumes 3 kg per day, the provisions available in the fort will last for 30 days. If some more soldiers join, the provisions available will last for 25 days given each soldier consumes 2.5 kg per day. Find the number of soldiers joining the fort in that case ?

A) 693 B) 741
C) 528 D) 654
 
Answer & Explanation Answer: C) 528

Explanation:

Assume x soldiers join the fort. 1200 soldiers have provision for 1200 (days for which provisions last them)(rate of consumption of each soldier)
= (1200)(30)(3) kg.

Also provisions available for (1200 + x) soldiers is (1200 + x)(25)(2.5) k

As the same provisions are available
=> (1200)(30)(3) = (1200 + x)(25)(2.5)

x = ([(1200)(30)(3)] / (25)(2.5)) - 1200 => x = 528.

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Filed Under: Ratios and Proportions
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

30 19625
Q:

Consider the following grouped frequency distribution:

  x           f

0-10       8

10-20     12

20-30     10

30-40      p

40-50      9

 

If the mean of the above data is 25.2, then what is the value of p?

 

A) 9 B) 10
C) 11 D) 12
 
Answer & Explanation Answer: C) 11

Explanation:
Mean = (sum of fixi/ (sum of f) = (8*5 + 12*15 + 10*25 + P*35 +9*45) / (8+12+10+P+9) = 25.2
(875 + 35P)/(39+P) = 25.2
P = 11
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Filed Under: Average
Exam Prep: Bank Exams

0 19607
Q:

Calculate the value of angle FED from the figure shown below.

 

 

A) 30 deg B) 40 deg
C) 60 deg D) 80 deg
 
Answer & Explanation Answer: B) 40 deg

Explanation:
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Filed Under: Area
Exam Prep: Bank Exams

0 19603
Q:

From a tank of petrol , which contains 200 liters of petrol, the seller replaces each time with kerosene when he sells 40 liters of petrol(or mixture). Everytime he sells out only 40 liters of petrol (pure or impure). After replacing the petrol with kerosene 4th time, the total amount of kerosene in the mixture is

A) 81.92L B) 96L
C) 118.08L D) None of these
 
Answer & Explanation Answer: C) 118.08L

Explanation:

The amount of petrol left after 4 operations = 200×1-402004=81.92 

 

Hence the amount of kerosene = 200 - 81.92 = 118.08 liters

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Filed Under: Alligation or Mixture

24 19594
Q:

Vinod have 20 rupees. He bought 1, 2, 5 rupee stamps. They are different in numbers by the reason of no change, the shop keeper gives 3 one rupee stamps. So how many stamps Vinod have ?

A) 10 B) 18
C) 12 D) 15
 
Answer & Explanation Answer: A) 10

Explanation:

Given total rupees = 20 Rs
No. of one rupee stamps = 3
Now, remaining money = Rs. 17
With that he buys only 2 and 5 rupee stamps
Let number of Rs. 5 stamps = K
Let number of Rs. 2 stamps = L
5K + 2L = 17
K = 3, L = 1 (possible)
L = 6, K = 1 (possible)
=> But given that they are different in number so, K is not equal to 3
one rupee stamps = 3
2 two stamps = 6
5 rupee stamps = 1
Total number of stamps = 10.

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Filed Under: Ratios and Proportions
Exam Prep: AIEEE , Bank Exams , CAT , GATE , GRE
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45 19547
Q:

Find the area of a triangle whose sides measure 13 cm, 14 cm and 15 cm.

A) 84 B) 64
C) 44 D) 22
 
Answer & Explanation Answer: A) 84

Explanation:

Let a = 13, b = 14 and c = 15. Then, s=12a+b+c=21

 (s- a) = 8, (s - b) = 7 and (s - c) = 6.


Area =ss-as-bs-c =21×8×7×6 = 84 sq.cm   

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Filed Under: Area
Exam Prep: Bank Exams
Job Role: Bank PO

40 19545
Q:

How many numbers up to 300 and 700 are divisible by 2, 3 and 7 both together ?

A) 7 B) 9
C) 11 D) 5
 
Answer & Explanation Answer: B) 9

Explanation:

LCM of 2, 3, 7 is 42.

=> (700 – 300)/42 = 9  22/42 => 9 Numbers.

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Filed Under: Numbers
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Bank Clerk , Bank PO

28 19543