suhir.kumar wrote:If x and y are positive integers , what is the value of xy??
(1)The greatest common factor of x and y is 10
(2)The least common multiple of x and y is 180
(1)The greatest common factor of x and y is 10.
If x = y = 10, then GCF of x and y = 10. Here xy = 10 * 10 = 100.
If x = 20, y = 10, then GCF of x and y = 10. Here xy = 20 * 10 = 200.
No definite answer; NOT sufficient.
(2) The least common multiple of x and y is 180.
If x = 1, y = 180, then LCM of x and y = 180. Here xy = 1 * 180 = 180.
If x = 10, y = 180, then LCM of x and y = 180. Here xy = 10 * 180 = 1800.
No definite answer; NOT sufficient.
Combining (1) and (2), GCF of x and y = 10 and LCM of x and y = 180
Note: If x and y are two positive integers, then LCM of x, y * GCF of x, y = x * y
So, xy = 10 * 180 = 1800; SUFFICIENT.
The correct answer is
C.
