but going forward if you could post OA's using SPOILER function then that would be much appreciatedcramya wrote:I would go with B)
I understand the OA's after some discussion part
To find if x is prime
Stmt I
x is positive
x+2 is prime
Lets say x+2 = 2
x=4 (not prime)
x+3 = 5
x=3 (prime)
INSUFF
Stmt II
x-7 = prime number
Lets say x-7 = 2(ONLY EVEN PRIME)
x=9 not prime
2 IS THE ONLY EVEN PRIME. The rest of the primes are odd
So x-7 = prime becomes x-7 = odd prime
x = 7+odd prime
x will always be even and will not be a prime (since odd+odd = even)
B)
Hope I have not missed anything here!
vittalgmat wrote:cramya wrote:I would go with B)
I understand the OA's after some discussion part
To find if x is prime
Stmt I
x is positive
x+2 is prime
Lets say x+2 = 2
x=4 (not prime)
x+3 = 5
x=3 (prime)
INSUFF
Stmt II
x-7 = prime number
Lets say x-7 = 2(ONLY EVEN PRIME)
x=9 not prime
2 IS THE ONLY EVEN PRIME. The rest of the primes are odd
So x-7 = prime becomes x-7 = odd prime
x = 7+odd prime
x will always be even and will not be a prime (since odd+odd = even)
B)
Hope I have not missed anything here!
Hi cramya,
I dint understand how it is B.
from 2. we have x -7 = prime# p.
x -7 = p
x = p +7.
SO x is any number that is 7 away from a prime #.
eg x = 3 + 7. x = 10, Not a prime
x = 2 +7. x = 9.
X could be any +ve # including a prime. So insufficient.
So once cannot say if x is prime. 2 is insufficient.
Have i missed something ??
thanks
-Vittal
