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# Aptitude - Arithmetic Online 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.

### Answer : B

### Explanation

Here a = 14, d = 9 - 14 = -5, n = 12 Using formula T_{n}= a + (n - 1)d T_{12}= 14 + (12 - 1) x -5 = -41

Q 2 - What digit should be placed in of H in 78423928H9 so as make it divisible by 9?

### Answer : D

### Explanation

For the number 78423928H9 to be divisible by 9, the sum of all its digits should be divisible by 9. So (7+8+4+2+3+9+2+8+2+9)/9 = (52+H)/9 = Number divisible by 9 So H should b replaced by 2

Q 3 - The difference between local and the face value of 8 in the numeral is 568012?

### Answer : C

### Explanation

8000 - 8 = 7992

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?

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

### Answer : B

### Explanation

Here numbers are 15, 18, ..., 105 which is an A.P. Here a = 15, d = 3, Using formula T_{n}= a + (n - 1)d T_{11}= 15 + (n - 1) x 3 = 105 => 12 + 3n = 105 => n = 93 / 3 = 31

### 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 - Sum of three numbers in G.P. is 28 and there product is 512. What are the numbers?

### Answer : C

### Explanation

let the numbers are a/r, a, ar Then a/r x a x ar = 512 => a^{3}= 8^{3}gt; a = 8 Now a/r + a + ar = 28 => 8/r + 8 + 8r = 28 => 8/r + 8r = 20 => 2/r + 2r = 5 => 2r^{2}+ -5r + 2 = 0 => 2r^{2}+ -4r -r + 2 = 0 => 2r(r-2) - (r-2)=0 => (r-2)(2r-1) = 0 => r = 2 or r = 1/2 ∴ numbers are 4, 8, 16.

Q 8 - One has to pay Rs 975 in yearly installments where each installment is less than earlier one by Rs 5. If first installment is of 100 in how many years, the entire amount will be paid?

### Answer : C

### Explanation

Here a = 100, d = -5 , S_{n}= 975 Using formula S_{n}= (n/2)[2a + (n-1)d] S_{n}= (n/2)[200 + (n-1)(-5)] = 975 => n(205 - 5n) = 1950 => 5n^{2}- 205n + 1950 = 0 => n^{2}- 41n + 390 = 0 => n^{2}- 26n - 15n + 390 = 0 => n(n-26) - 15(n-26)= 0 => (n-26)(n-15) => n = 15

### Answer : D

### Explanation

Here a = 3, d = 5 - 3 = 2, n = 18 Using formula T_{n}= a + (n - 1)d T_{18}= 3 + (18 - 1) x 2 = 37

Q 10 - If 1^{2} + 2^{2} ... + 20^{2} = 2870. What is 2^{2} + 4^{2} +... + 40^{2}?

### Answer : C

### Explanation

(2^{2}+ 4^{2}... + 40^{2}) = (1 x 2^{2}+ 2^{2}x 2^{2}+ 3^{2}x 2^{2}+... + 20^{2}x 2^{2}) = 2^{2}(1^{2}+ 2^{2}+ .... + 20^{2}) = 4 x 385 = 1540