Last Updated on May 9, 2023
Is RST…
Solution:
We need to determine whether RST = 1.
Statement One Alone:
RS = 1
Since we don’t know the value of T, knowing only that RS = 1 is not sufficient to determine whether RST = 1. We can eliminate answer choices A and D.
Statement Two Alone:
ST = 1
Since we don’t know the value of R, knowing only that ST = 1, is not sufficient to determine whether RST = 1. We can eliminate answer choice B.
Statements One and Two Together:
From statements one and two we know that RS = 1 and that ST = 1. Thus, we can say that:
RS = ST
RS – ST = 0
S(R – T) = 0
S = 0 or R = T
Because RS and ST both equal 1, S cannot be 0. Thus, R = T.
However, knowing that R = T is not enough information to determine whether RST = 1.
For example, if R = T = 1, then S = 1 (since RS = 1 and ST = 1), RST = 1.
However, if R = T = 2, then S = ½ (since RS = 1 and ST = 1), RST = 2 [Symbol] 1.
Answer: E
