BTGModeratorVI wrote: ↑Sat Mar 14, 2020 6:28 am
3r ≤ 4s + 5
|s| ≤ 5
Given the inequalities above, which of the following CANNOT be the value of r?
A. –20
B. –5
C. 0
D. 5
E. 20
Answer: E
Source: Official Guide
\(3r-4s \le 5\)------ 1
\(5 \ge s \ge -5\)-------2
Now lets put answer options in equation 1 keeping equation 2 in mind
\(r=-20\). Even if \(s\) takes the smaller value -5 or +5, it will always be less than 5
\(r= -5\). If \(s\) is +5 then the value of equation 1 will be less than 5
\(r=0\). If \(s=+5\) than the value of equation 1 will be less than 5
\(r=5\). If \(s= +5\) than the value of equation 1 will be less than 5
\(r=20\). It doesn't matter whether the value of s is maximum or minimum, the value of equation 1 will always be greater than 5
E is the correct answer.