# 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. Q 1 - What is y if 2y, y+10, 3y+2 are in an A.P.?

A - 4

B - 5

C - 6

D - 8

### Explanation

```
As numbers are in A.P.
Thus (y + 10) - 2y = (3y + 2) - (y + 10)
=> 10 - y = 2y - 8
=> -3y = -18
=> y = 6  ```

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

A - 0

B - 6

C - 8

D - 4

### 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 value of (3n+3n-1)/(3n+1-3n) is?

A - 5/2

B - 3/2

C - 2/3

D - 1/3

### Explanation

```
(3n+3n-1)/(3n+1-3n)  = (1+3-1)/ (3-1)
= 2/3  ```

Q 4 - If 123 is subtracted from the square of a number, the answer so obtained is 976. What is the number?

A - 58

B - 56

C - 54

D - 52

### Explanation

```
Let the number be x.
According to question:
x2 - 123 = 976
or, x = 52 ```

Q 5 - What is next in 2, 5, 8,...?

A - 7

B - 9

C - 10

D - 11

### Explanation

```
Here numbers are 2, 5, 8, ... which is an A.P. Here a = 2,  d = 3,
So next number will be 8 + 3 = 11. ```

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

A - 3750

B - 6200

C - 6500

D - 7500

### Explanation

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

Q 7 - What is the sum of (1 + 1/2 + 1/4 + ...)?

A - 2

B - 4

C - 8

D - 10

### Explanation

```
This is an infinite G.P. with a = 1 and r = 1/2.
Sum of infinite G.P. = a/(1-r)  = 1/(1-1/2)  = 1/(1/2)  = 2 ```

Q 8 - 12 + 22 ... + x2 = [x(x+1)(2x+1)]/6. What is 12 + 32 +... + 192?

A - 1330

B - 2100

C - 2485

D - 2500

### Explanation

```
(12 + 32 ... + 192)  = (12 + 22 ... + 192) - (22 + 42 ... + 182)
Using formula  (12 + 32 ... +  n2) = [n(n+1)(2n+1)]/6  [19(19+1)(38+1)]/6 - (1 x 22 +  22 x 22 + 22 x  32 + ... + 22 x  92)
= 2470 - 22(12 + 22 + ... + 92)
= 2470 -  (4 x 9 x 10 x 19)/6
= 2470 - 1140
= 1330 ```

Q 9 - What is the 115th term of A.P. 4, 4.5, 5, 5.5 ... ?

A - 56

B - 55.5

C - 59

D - 55

### Explanation

``` Here a = 4, d = 4.5 - 4 = 0.5, n = 115
Using formula Tn = a + (n - 1)d
T115 = 4 + (115 - 1) x 0.5
= 59 ```

Q 10 - How many 2 digits numbers are there which are divisible by 6?

A - 12

B - 15

C - 16

D - 17

```