Mathmetics
ISBT Mathmetics for all banking PO,Clerk,IBPS PO,Railway,SSC,IAS,OAS Exams
Q1. | If 2x2 -7xy +3y2 = 0 ,then the value of x:y = ? |
1) | 3:2 | 2) | 2:3 |
3) | 3:1 and 1:2 | 4) | 5:6 |
5) | None of these |
Answer : 3:1 and 1:2
Explanation : Given, 2x2 -7xy +3y2 = 0
Explanation : Given, 2x2 -7xy +3y2 = 0
or 2(x/y)2-7(x/y)+ 3 = 0
So, x/y=3/1 and x/y=1/2

Q2. | If a,b and c are real numbers such that a-b+c <1 , a+b+c >1 and 9a+3b+c < -4, then what is the sign of 'a'? |
1) | + only | 2) | - only |
3) | + or - | 4) | Can't be said |
5) | None of these |
Answer : - only

Q3. | If a,b and c are the two roots of a quadratic equation such that a+b =24 and a-b = 8, the quadratic equation having a and b as its roots is ---. |
1) | x2+2x+8=0 | 2) | x2-4x+8=0 |
3) | x2-24x+128=0 | 4) | 2x2+8x+9=0 |
5) | None of these |
Answer : x2-24x+128=0
Explanation : Given, a+b =24 and a-b = 8
Explanation : Given, a+b =24 and a-b = 8
So,solving from two equations,we get a =16 and b=8
Therefore,ab=16 x 8 = 128
Quadratic equations
x2 - ( sum of roots)x + products of the roots = 0
or x2-24x+128 = 0

Q4. | What is the value of 'P' , if the following equation has two equal roots ? |
1) | P=6 or P=-2 | 2) | P=4 or P=-3 |
3) | P=6 or P=-3 | 4) | P=4 or P=2 |
5) | None of these |
Answer : P=6 or P=-2
Explanation : Here, a=4,b= - (P-2); c=1
Explanation : Here, a=4,b= - (P-2); c=1
Given, equation has equal roots,then D=0
b2- 4ac =0
or p2 +4 - 4p - 16 = 0
or p2- 6p +2p - 12 =0
or p(p-6) + 2(p-2) = 0
or p=6 or -2
