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 - If an A.P. have 4th term as 14 and 12th term as 70. What will be its 17th term?

A - 108

B - 107

C - 106

D - 105

Answer : D

Explanation

  
Let's have first term as a, common difference is d then  
a + 3d = 14 ... (i)  
a + 11d = 70 ... (ii)  
Subtracting (i) from (ii)  
=> 8d = 56  => d = 7  
Using (i)  
=> a = 14 - 3d  = -7  
Using formula Tn = a + (n - 1)d    
T17 = -7 + (17 - 1) x 7 = 105  

Q 2 - Find the unit digit of 415 x 66?

A - 0

B - 6

C - 8

D - 4

Answer : D

Explanation

  
Unit digit of 415 is 4 and unit digit of  66  is 6.  
So unit digit of 415 x 66  will be 4 x 6 =24 i.e., 4.  

Q 3 - The sum of first 99 natural numbers is?

A - 9801

B - 9800

C - 4851

D - 4950

Answer : D

Explanation

  
 Sum of n natural numbers is  Sn=n(n+1)/2  =99(99+1)/2  
 =4950  

Q 4 - The difference between 58% and 39% of a number is 247. What is 62% of that number?

A - 1300

B - 806

C - 754

D - 1170

Answer : B

Explanation

  
 Let the number be y.  
 According to question,       (58 - 39)% of y = 247  
 Or, y x (19/100) = 247  
 Or, y = 1300  
 ∴62% of 1300 = (62/100) x 1300 = 806 

Q 5 - How many multiples of 3 are available between 15 and 105 including both?

A - 30

B - 31

C - 32

D - 33

Answer : B

Explanation

 
 Here numbers are 15, 18, ..., 105 which is an A.P. 
 Here a = 15,  d = 3,    
 Using formula Tn = a + (n - 1)d    
 T11 = 15 + (n - 1) x 3 = 105 
 => 12 + 3n = 105 
 => n = 93 / 3 = 31 

Q 6 - if a, a-2 and 3a are in an A.P. what is a?

A - -3

B - -2

C - 2

D - 3

Answer : B

Explanation

 
 As a, a-2 and 3a are in an A.P. 
 ∴ (a-2) - a = 3a - (a-2) 
 => -2 = 2a - 2 
 => a = -2 

Q 7 - If third term of a G.P. is 4. What will be the product of first 5 terms?

A - 43

B - 44

C - 45

D - 46

Answer : C

Explanation

  
 Using formula Tn = arn- 1 
 T3 = a x r(3-1) = 4  
 => ar2 = 4  
 Thus product of first five terms  = a x ar x ar2 x ar3 x ar3  
 = a5r10  
 = (ar2)5  
 = 45 

Q 8 - If a clock buzzes 1 time at 1 o'clock , 2 times at 2 o'clock and so on then how many times it buzzes in a day?

A - 100

B - 150

C - 156

D - 166

Answer : C

Explanation

  
 Total buzzes = 2(1 + 2 + 3 ... + 12)   
 Here a = 1, d = 1 , l = 12   
 Using formula Sn = (n/2)[a+l]   
 Sn = (12/2)[1+12]  = 6 x 13  = 78 
 Thus total number of buzzes = 2 x 78 = 156. 

Q 9 - What is y if 2y, y+10, 3y+5 are in an A.P.?

A - 4

B - 5

C - 6

D - 8

Answer : B

Explanation

    
 As numbers are in A.P.  Thus (y + 10) - 2y = (3y + 5) - (y + 10)  
 => 10 - y = 2y - 5  
 => -3y = -15  
 => y = 5  

Q 10 - (13 + 23 ... + 203) - (1 + 2 + ... + 20)= ?

A - 43950

B - 43970

C - 43980

D - 43960

Answer : C

Explanation

  
 Using formula  (13 + 23 ... +  n3) = [(1/2)n(n+1]2  
 (13 + 23 ... + 203) = [(20 x 21)/2]2  = 2102  = 44100  
 Using formula  (1 + 2 + ... n) = [(1/2)n(n+1]  
 ∴ (13 + 23 ... + 153) - (1 + 2 + ... + 15) = 44100 - (1/2) x 15 x 16 
 = 44100 - 120  
 = 43980 

aptitude_arithmetic.htm

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