BTGModeratorVI wrote: ↑

Mon Sep 14, 2020 8:37 am

Last year Publisher X published 1,100 books, consisting of first editions, revised editions, and reprints. How many first editions did Publisher X publish last year?

(1) The number of first editions published was 50 more than twice the number of reprints published.
(2) The number of revised editions published was half the number of reprints published.

Answer: C
Source: Official guide

Given: Last year Publisher X published 1,100 books, consisting of first editions, revised editions, and reprints.
Let F = number of first editions
Let V = number of revised editions
Let P = number of reprints

We can write: F + V + P = 1100

Target question: What is the value of F

Statement 1: The number of first editions published was 50 more than twice the number of reprints published.
We can write: F = 2P + 50
We also know: F + V + P = 1100
Since we have 2 equations with 3 variables, we cannot solve this system for F
Statement 1 is NOT SUFFICIENT

Statement 2: The number of revised editions published was half the number of reprints published.
We can write: V = P/2
Rewrite as: 2V = P
We also know: F + V + P = 1100
Since we have 2 equations with 3 variables, we cannot solve this system for F
Statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
The given information tells us that F + V + P = 1100
Statement 1 tells us that F = 2P + 50
Statement 2 tells us that 2V = P

Since all 3 equations are DIFFERENT, we COULD solve the system for F, V and P, which means we COULD answer the target question with certainty (although we'd NEVER do this, since it would be a waste of precious time!)

The combined statements are SUFFICIENT

Answer: C

Cheers,
Brent