Num prp

Thanks Anurag!
This means we can answer any such questions just by looking at it!

Just being curious, can you show some numbers?

St 1 gives P can be 7 or 17 or 31

Insufficient

St 2 : P can be 11 or 31 or 71.

Insufficient.

Pick E

Anurag,

Just to clarify the logic here, are we trying to find intersections of the two statements? To re-state, is there only one intersection (at 31) that the two statements below satisfy?

I did this by listing numbers and identifying overlaps. I think 1, 31, 71 works for both. I actually stopped at 1 and 31. I could be wrong here, but isn't statement 1 a parabola and statement two linear? Why is there more than 2 intersections, as you noted 71 also works.



[quote="Anurag@Gurome"][quote="yellowho"]Is the prime number p equal to 31 ?

(1) p is equal to one less than twice the value of the square of an integer.
(2) p is equal to four less than a multiple of …5[/quote]

I can show you numbers, but if you know the fact that there is no particular formula or relation by which we can uniquely point out prime numbers, you can easily answer that both question together is NOT sufficient to answer the problem.

Because there will be infinite number of primes which will satisfy any bunch of properties at the same time unless the properties point to a particular prime. For example, if the property is like "p is 1 greater than LCM of 5 and 6", then it uniquely points to 31. But if the properties are general, i.e. like the ones given in the question, then they can never point to a particular prime.

[spoiler]The correct answer is E.[/spoiler][/quote]