Aptitude - Questions & Answers

Aptitude - Arithmetic Online Quiz

Quiz

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.

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

Answer : C

Explanation

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

Q 2 - Find two natural numbers whose sum is 72 and the least common multiple is 429?

Answer : C

Explanation

  S
Sum x+y=72  
Lcm of 39 & 33 is 429

Q 3 - If 3^X-1 +3^X+1 = 270, then X=?

Answer : D

Explanation

  
 3^{X-1^{+3^X+1 = 270  
 => 3^X(3^-1+3¹) = 270  
 => 3^X x (10/3) = 270  
 => 3^X-1 = 270/10 
 = 27 
 =3³  
 => X-1=3  
 => X=4}}

Q 4 - ((991+771)2-(991-771)2)/(991x771)=?

Answer : C

Explanation

 
 ((991+771)2-(991-771)2)/(991x771)=((A+B)2-(A-B)2)/(AxB)  
 (4xAB)/AB=4

Q 5 - The average of four consecutive even numbers is one- fourth of the sum of these numbers. What is the difference between the first and the last number?

Answer : B

Explanation

  
 Let the four consecutive even numbers are x, x + 2, x + 4 and x + 6.  
 ∴ Required difference = x + 6 - x = 6

Q 6 - What is the sum of all odd numbers between 100 and 200?

Answer : D

Explanation

  
 Required sum = 101 + 103 + ... + 199 which is an A.P. where a = 101, d = 2, l = 199.  
 Using formula T_n = a + (n - 1)d  
 T_n = 101 + (n-1)2 = 199  
 => 2n = 199 - 99 = 100  
 => n = 50  
 Now Using formula S_n = (n/2)(a + l)  
 ∴ Required sum = (50/2)(101+199)  = 50 x 150  = 7500

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

Answer : C

Explanation

  
 Here a = 2,  r = 3, n = 8. 
 Using formula T_n = ar^{n- 1} 
 T_n = 2 x 3^(8-1)  
 =2 x 3⁷  
 =2 x 2187  =4374

Q 8 - (1³ + 2³ ... + 15³) = ?

Answer : D

Explanation

  
 Using formula  (1³ + 2³ ... +  n³) = [(1/2)n(n+1]²  
 (1³ + 2³ ... + 15³) 
 = [(15 x 16)/2]²  
 = 120²  = 14400

Q 9 - Which term of 2, 7, 12, 17... is 92?

Answer : D

Explanation

  
 Here a = 2,  d = 7 - 2 = 5,  
 Let there be n term.  
 Using formula T_n = a + (n - 1)d  
 T_n = 2 + (n - 1) x 5 = 92  
 => 5n - 3 = 92  
 => n = 19

Q 10 - If 1² + 2² ... + 20² = 2870. What is 2² + 4² +... + 40²?

Answer : C

Explanation

   
 (2² + 4² ... + 40²)  = (1 x 2² + 2² x 2² + 3² x 2² +... +  20² x 2²)  
 = 2²(1² + 2² + .... + 20²) 
 = 4 x  385  
 = 1540

aptitude_arithmetic.htm

Print Page