For integers x and y, if 91x = 8y, which of the following must be true?
I. y > x
II. y/7 is an integer
III. The cube root of x is an integer
Options: A) I only B) II only C) III only D) I and II E) II and III
Given 91*x=8*y   It can be equal when x = 8 or -8   and y = 91 or -91   So Statement (I) y &lt; x if we take x = -8 and y =-91   but y &gt; x if we take x = 8 and y = -91, so (I) is not true always   Statement (2) in any case   91/7 or -91/7 is an integer that is 13 or -13. So it is true   Statement (3) cube root of 8 or -8 is 2 and -2 respectively. So it is true always.   answer is II and III
<result>E</result>
For integers x and y, if 91x = 8y, which of the following must be true?
I. y > x
II. y/7 is an integer
III. The cube root of x is an integer