# 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 - If nth term of the series 72, 63, 54, ... is 0. What is n?

A - 8

B - 9

C - 10

D - 11

### Explanation

```
Here a = 72,  d = 63 - 72 = -9,
Using formula Tn = a + (n - 1)d
Tn = 72 + (n - 1) x -9 = 0
=> 81 - 9n = 0
=> n = 9
```

Q 2 - Find the number which being increased by 1 will be exactly divisible by 13, 15 and 19?

A - 3704

B - 3706

C - 3705

D - 3715

### Explanation

```
LCM of 13, 15 and 19 is 3705
So the desired number is3705-1=3704  ```

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

A - 9801

B - 9800

C - 4851

D - 4950

### 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

### 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 numbers between 10 and 200 are exactly divisible by 7?

A - 21

B - 23

C - 25

D - 27

### Explanation

```
Here numbers are 14, 21, ..., 196 which is an A.P.
Here a = 14,  d = 21 - 14 = 7,
Using formula Tn = a + (n - 1)d
Tn = 14 + (n - 1) x 7 = 196
=> 7 - 7n = 196
=> n = 189 / 7 = 27 ```

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 - If 4th and 9th terms of a G.P. are 54 and 13122 then what will be the 2nd term?

A - 6

B - 12

C - 18

D - 9

### Explanation

```
Using formula Tn = arn- 1
T4 = ar(4 - 1)
=> ar3 = 54 ... (i)
T9 = ar(9 - 1)
=> ar8 = 13122 ... (ii)
Dividing (ii) from (i)
=> r5 = 243 = 35
=> r = 3
Using (i)  a = 54 / 9 = 6 ```

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

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

A - 770

B - 1155

C - 1540

D - 3852

### 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