nikolas7
In this case p can also be a different number?
What i mean is that it could be a very big number which we can not calculate so easy as 12. How we can be sure that 12 is the right answer, if what i refer is correct?
If p is a positive integer, what is the value of p?
1) p/4 is a prime #.
2) p is divisible by 3.
Sol: St 1 P/4 is prime so p=8,12,20,28 and so on or P is an odd multiple of 4 (Barring 8 which is an even multiple of 4 and 2 is only even prime no ). Not Sufficient
St 2 p=3I where I is an integer so p=3,6,9,12 and so one
Combining we get p is a multiple of 3 and p/4 is prime. Only 12 fits. Note that you will not have a number where both the conditions are satsified.
Consider p/4= prime (11,23,29...)
p= 44,92,116
Thus p will be a multiple of 2 and 4 but not of 3.
If p is divisible by 3 then barring 12 for no other number can you get p/4 =prime