Aptitude - Arithmetic Online Quiz


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Following quiz provides Multiple Choice Questions (MCQs) related to Basic Arithmetic. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Questions and Answers

Q 1 - Which term of 2,7, 12,17... is 87?

A - 16th

B - 17th

C - 18th

D - 15th

Answer : C

Explanation

  
Here a = 2,  d = 7 - 2 = 5,  
Let there be n term.  
Using formula Tn = a + (n - 1)d  
Tn = 2 + (n - 1) x 5 = 87  
=> 5n - 3 = 87  
=> n = 18 

Q 2 - If X and Y are two different prime numbers, then find the number of divisors of X2Y2?

A - 3

B - 9

C - 6

D - 7

Answer : B

Explanation

 
X2Y2 = X2 x Y2  
Number of divisors = (2+1)(2+1)= 9  

Q 3 - The least prime number is?

A - 3

B - 2

C - 1

D - 0

Answer : B

Explanation

2 is the least prime number.

Q 4 - Two numbers are less than the third number by 50% and 54% respectively. By how much percent is the second number less than the first number?

A - 13

B - 10

C - 12

D - 8

Answer : D

Explanation

 
 Let the third number be 100. 
 ∴First Number = 50 and Second Number = 46 
 Decrease = 50 - 46 = 4 
 ∴Required Percentage = (4/50)x100 = 8% 

Q 5 - If 10th term of A.P. a, a-b, a-2b, ... is 20 and 20th term is 10 then what will be xth term?

A - 10-x

B - 20-x

C - 29-x

D - 30-x

Answer : D

Explanation

  
 Here a = a-b,  d = (a-2b) - (a-b) = -b,    
 Using formula Tn = a + (n - 1)d    
 T10 = (a-b) + (10 - 1) x (-b) = 20    
 => a - 9b = 20 ... (i) 
 T20 = (a-b) + (20 - 1) x (-b) = 10    
 => a - 19b = 10 ... (ii) 
 Subtracting (ii) from (i) 10b = 10 
 => b = 1 
 Using (i) a - 9(1) = 20 
 => a = 29 
 ∴ xth term = a + (x-1)d 
 = a + (x-1)(-b) = 20 + (x-1)(-1) 
 = 30-x 

Q 6 - How many odd numbered pages are present in a book of 1089 pages?

A - 542

B - 543

C - 544

D - 545

Answer : D

Explanation

 
 Here pages are 1, 3, ..., 1089 which is an A.P. Here a = 1,  d = 2, l = 1089    
 Using formula Tn = a + (n - 1)d 
 Tn = 1 + (n - 1) x 2 = 1089 
 => 2n -1 = 1089 
 => n = 1090 / 2 = 545 

Q 7 - What is the 8th term of G.P. 2, 6, 18,...?

A - 2187

B - 6561

C - 4374

D - 6664

Answer : C

Explanation

  
 Here a = 2,  r = 3, n = 8. 
 Using formula Tn = arn- 1 
 Tn = 2 x 3(8-1)  
 =2 x 37  
 =2 x 2187  =4374 

Q 8 - One has to pay 3600 in 40 installments which are in A.P. After 30th installment being paid, amount left will be one third. What will be the 8th installment?

A - 35

B - 50

C - 65

D - 75

Answer : C

Explanation

   
 Installments = 40, Total debt = 3600  Installments = 30, 
 Total debt = (2/3) x 3600 = 2400  
 Let the installments be a, a + d, a + 2d, ...  
 Using formula Sn = (n/2)[2a+(n-1)d]   
 S30 = (30/2)[2a+(30-1)d] = 3600  
 => 2a + 29d = 160 ... (i)  
 S40 = (40/2)[2a+(40-1)d] = 2400  
 => 2a + 39d = 180 ... (ii)  
 Subtracting (i) from (ii)  
 => 10d = 20  
 => d = 2  
 Using (i)  2a = 160 - 29d = 160 - 58 = 102  
 => a = 51  
 Using formula Tn = a + (n-1)d  
 ∴ T8 = 51 + 7 x 2 = 51 + 14  = 65 

Q 9 - If an A.P. have 4th term as 16 and 12th term as 80. What will be its common difference?

A - -10

B - -7

C - 8

D - 10

Answer : C

Explanation

  
 Let's have first term as a, common difference is d then  
 a + 3d = 15 ... (i)  
 a + 11d = 80 ... (ii)  
 Subtracting (i) from (ii)  
 => 8d = 64  
 => d = 8  

Q 10 - If nth term of the series 72, 63, 54, ... is 9. What is n?

A - 8

B - 9

C - 10

D - 11

Answer : A

Explanation

   
 Here a = 72,  d = 63 - 72 = -9,    
 Using formula Tn = a + (n - 1)d    
 Tn = 72 + (n - 1) x -9 = 9    
 => 81 - 9n = 9   
 => n = 8   

aptitude_arithmetic.htm

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