-
hareesh860
- Senior | Next Rank: 100 Posts
- Posts: 31
- Joined: Fri Oct 01, 2010 8:27 am
- Thanked: 2 times
(1) The product of x and y is 7.hareesh860 wrote:What is the value of (x - y)^4?
(1) The product of x and y is 7.
(2) x and y are integers.
If x = 7, y = 1, then (x - y)^4 = 6^4, which will given an integer value.
If x = 49, y = 1/7, then (x - y)^4 = (49 - 1/7)^4, which will give a fractional value.
If x = -7, y = -1, then (x - y)^4 = (-7 + 1)^4 = (-6)^4, which will given an integer value.
So, there can be many other values of x and y for which their product is 7. No definite answer. So, statement 1 is NOT sufficient.
(2) x and y are integers implies x and y can take many values and accordingly (x - y)^4 will give different answers. No definite answer. So, statement 2 is NOT sufficient.
Combining (1) and (2), we know x and y are integers. So, the possible values are:
x = 7, y = 1 or x = 1, y = 7
x = -7, y = -1 or x = -1, y = -7
In all the cases, (x - y)^4 will give the same integer value, 6^4; SUFFICIENT.
The correct answer is C.
