(1) r = s = tgilm wrote:if pqrst=4 , is p=1/q
stat 1) r=s=t
stat 2) three of pqrst are integers.
pq * r^3 = 4
Now in case p = 1/q, then rst = 4 or r^3 = 4 or r = (4)^(1/3) but this is not confirmed as r may or may not be (4)^(1/3); NOT sufficient.
(2) Three of pqrst are integers implies if p = 2 then q = 1/2, not an integer.
If p = 1, then q = 1, an integer.
Still not confirmed if p = 1/q; NOT sufficient.
Combining (1) and (2), If r = s = t = 1, an integer, then pq * 1 = 4, which cannot be true if p = 1/q
If r = s = t = 2, then pq * 8 = 4, which is again not true if p = 1/q. So, p is not equal to 1/q; SUFFICIENT.
The correct answer is C.
