Mathmetics
ISBT Mathmetics for all banking PO,Clerk,IBPS PO,Railway,SSC,IAS,OAS Exams
Q1. | If x=2015, y=2014 and 2013 , then x2+y2+z2 -xy-yz-zx = ? |
1) | 2 | 2) | 3 |
3) | 4 | 4) | 6 |
5) | None of these |
Answer : 3
Explanation : ATQ: x2+y2+z2 -xy-yz-zx
Explanation : ATQ: x2+y2+z2 -xy-yz-zx
= x2-xy+y2 -yz+z2-zx
= x(x-y) + y((y-z) + z(z-x)
= 2015(2015-2014) + 2014(2014-2013)+2013(2013-2015)
= 2015 + 2014 + 4026
=4029-4026 =3

Q2. |
1) | 8 | 2) | 9 |
3) | 10 | 4) | 12 |
5) | None of these |
Answer : 10
Explanation :
Explanation :
Given, x2 + 9/x = 6x
Or x2 - 6x = 9
Or (x-3)2 = 0
Or x = 3
So, x2 + 9/x2 = 10

Q3. |
|
1) | 221 | 2) | -231 |
3) | -253 | 4) | 0 |
5) | None of these |
Answer : -253
Explanation :
Explanation :
Given, a = 4/3
Or 3a = 4
Or 3a - 4 = 0
Or (3a-4)3 = 27a3 - 108a2 + 144a - 64 = 03
Or 27a3 - 108a2 + 144a - 317 = (27a3 - 108a2 + 144a -64) - 153 = 0 - 253 = - 253

Q4. |
1) | 0 | 2) | 1 |
3) | 2 | 4) | 3 |
5) | None of these |
Answer : 3
Explanation :
Explanation :


Q5. |
1) | 21 | 2) | 23 |
3) | 25 | 4) | 27 |
5) | None of these |
Answer : 23
Explanation : We know that,
Explanation : We know that,


Q6. |
1) | 1 | 2) | 2 |
3) | 4 | 4) | 5 |
5) | None of these |
Answer : None of these
Explanation :
Explanation :

