**1).(1015)2 = ?**

**(A)** 1040125

**(B)** 1030225
**(C)** 1050125
**(D)** 1025125

*Answer:(B)*

__Explanation:__

```
10152 = (1000+15)2
= 10002 + 152 +2 x 1000 x 15
```

2).Which one is NOT divisible by 3 ?

**(A)** 5271

**(B)** 6291

**(C)** 4372

**(D)** 8952

*Answer:(C)*

__Explanation____:__
If the total of digits is divisibble by 3, number is also divisible by 3
5271……..5+2+7+1=15 is divisible by 3
6291……..6+2+9+1=18 is divisible by3
4372……..4+3+7+2=16 is not divisible by 3
8952……..8+9+5+2=24 is divisible by 3

3).Largest five digit number exactly divisible by 39 is:

**(A)** 99979

**(B)** 99956

**(C)** 99989

**(D)** 99996

*Answer:(D)*__Explanation:__

```
Largest 5 digit number is 99999.
Let us divide 99999 by 39
39) 99999 (2564
78
-----
219
195
-----
249
234
-----
159
156
----
3
From above calculation, we know 39*2564 + 3 = 99999
Therefore 99999-3 = 99996 is the largest divisible number by 39.
```

4).Which is not the prime number?

**(A)** 43

**(B)** 57

**(C)** 73

**(D)** 101

*Answer:(B)*

**Explanation****:** A positive natural number is called prime number if nothing divides it except the number itself and 1. 57 is not a prime number as it is divisible by 3 and 19.

5).103 x 103 + 97 x 97 = ?
**(A)** 21348
**(B)** 20018
**(C)** 19648
**(D)** 21428
*Answer:** **(B)***Explanation:**

```
103 x 103 + 97 x 97
= (100+3)2 + (100-3)2
= 2 (1002 + 32 )
[ (X +Y)2 + ( X – Y)2 = 2 ( X2 + Y2 ) ]
= 2 (10000 + 9 )
= 2 x 10009
= 20018
```

6).9848 x 125 = ?
**(A)** 1232000
**(B)** 1242000
**(C)** 1231000
**(D)** 1233000

*Answer:** **(C)***Explanation:**

```
9848 x 125 = 9848 x (250 / 2)
= 4924 x (500 / 2)
= 2462 x (1000 / 2)
= 1231 x (1000)
= 1231000
```

7).How many of the following numbers are divisible by 9 96381, 46729, 54459, 85369, 46818

**(A)** 1
**(B)** 2
**(C)** 4
**(D)** 3
*Answer:** **(D)***Explanation:** If sum of digits are divisible by 9, number is also divisible by 9

```
96381…..9+6+3+8+1= 27 (/)
46729…..4+6+7+2+9= 28 (x)
54459…..5+4+4+5+9= 27 (/)
85369…..8+5+3+6+9= 31 (x)
46818…..4+6+8+1+8= 27 (/)
```

8).What will be the next number? 3, 5, 7, 11, 13, 17…….

**(A)** 21
**(B)** 19
**(C)** 25
**(D)** 20
*Answer:** **(B)***Explanation:** This is a sequence of prime numbers