BTGModeratorVI wrote: ↑Sat Jun 13, 2020 5:37 am
What is the average of x and y?
1) x + y = 20
2) 2x + 4y = 54
Answer:
A
Source: Veritas Prep
Target question: What is the average of x and y?
Average of x and y = (x + y)/2
So, to find the average, we need only find the value of x+y
Statement 1: x + y = 20
Perfect!
So, average = (x + y)/2
= 20/2
=
10
Since we can answer the
target question with certainty, statement 1 is SUFFICIENT
Statement 2: 2x + 4y = 54
Divide both sides by 2 to get: x + 2y = 27
This doesn't help, because we need the value of x + y.
To understand why this statement is not sufficient, let's test some values. There are several values of x and y that satisfy statement 2. Here are two:
Case a: x = 1 and y = 13, in which case
the average of x and y = (1+13)/2 = 7
Case b: x = 9 and y = 9, in which case
the average of x and y = (9+9)/2 = 9
Since we cannot answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Answer = A
Cheers,
Brent
