Is x 5 ? (1) x^2 25 (2) 2x + 7 0

Question

Is x > 5 ?

(1) x^2 > 25
(2) 2x + 7 > 0

Sasindran · Answer

E

From st1 we get x>-5 or x>5. Two values are possible. Hence insufficient.

From st2 2x+7>0

X>-3.5 x can be either greater than 5 or less than 5. Hence insufficient 
Combining still x can be greater than or less than 5. Hence insufficient

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exc4libur · Answer

St.1: x > 5 or x < -5 ; ins St.2: 2x + 7 > 0 , x > -3.5 ; ins St.1&2: If x > -5 = -6 and we plug it into St.2: "2(-6) + 7 < 0" the condition becomes false. So, x > 5 answers is (C).

akshata19 · Answer

hey i arrived at C too but i think there is some discrepancy in above solution St1 : x^2 > 25 means x>5 or x < -5 ...... but no definite ans OK ii.) x<-5 assume x=-6 (-6)^2 >25 OK -6 <-5 ] St2 : 2x + 7 > 0 , x > -3.5 Combining , x>5 as x<-5 does not satisfy the 2nd condtn

exc4libur · Answer

Hi ak,
Could you be more specific? Sorry.

ManSab · Answer

Is x > 5 ?

(1) x^2 > 25
(2) 2x + 7 > 0

============

1) x^2 > 25
X > 5 and X < -5
not sufficient

2) 2x + 7 > 0
x > - 3.5
not sufficient

Combine 1 & 2
let us say X = -2 , satisfy X > -3.5 but doesn't satisfy X > 5 or X < -5
let us say X = 6 , satisfy both X > -3.5 and X > 5

Answer - E.

mihir0710 · Answer

Statement 1 : x^2 > 25 Means, either x>5 or x<-5 So, we cannot be 100% sure of whether x>5. Hence, this statement is insufficient. Statement 2 : 2x+7>0 which is equivalent to 2x > 7 or further, x > 3.5 So, this can give us any value between 3.6 to infinity. Hence, we cannot be 100% sure of whether x>5. Again, INSUFFICIENT So, combining, we know from st-1 that x>5 or x<-5 But st-2 says, x>3.5 So, the possibility that x<-5 is NOT valid. Hence, we are left with, x>3.5 and x>5, so obviously, x>5 and we answer the question with a definite YES. So, option C

mbaapplicant2019 · Answer

From 1: x^2 >25 => X>5 or X<-5 => not suff

From 2: 2x+7>0 => X>-3/5 => not suff

From 1 and 2, X>5 => Suff. Answer C

Please kudo if it's help.

nitiny · Answer

IMO C

1> 5>X and X <-5 not sufficient

2> 2X > 7 --> x > -3.5 not sufficient

combining both X>5

sanjayparihar16 · Answer

Problem Statement x>5? we need a definite YES or a definite NO
Statement 1->
x^2>25
Let's try to invalidate the expression by plugging in some values from the range mentioned in problem statement;
x=6 -> x^2=36 -> 
Hence, x>5 and YES
But if x=-6?
x^2=36; Statement 1 is sufficed but we get a NO for problem statement
Hence Statement 1 alone is not sufficient.

Statement 2->
2x+7>0
Clearly it is not sufficient alone, let's consider both the statements now;

From the statement 1 we know that negative values are the ones that causes problem in case of squaring, let's check for those cases only as we know that it would always be true for all the positive values of x
Let's take x=-6 and statement 2 falls for x=-6 as -12+7=-5 which is not positive, hence we get the surety here that x is not less than -5

Thus we can say that by combining both the statements, we can arrive at our answer.

OPTION C

Is x > 5 ? (1) x^2 > 25 (2) 2x + 7 > 0

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