Data Sufficiency

Source: Official Guide

How many newspapers were sold at a certain newsstand today?

1. A total of \(100\) newspapers were sold at the newsstand yesterday, \(10\) fewer than twice the number sold today.

2. The number of newspapers sold at the newsstand yesterday was \(45\) more than the number sold today.

The OA is A

BTGmoderatorLU wrote: ↑

Sat Jun 24, 2023 7:58 am

Source: Official Guide

How many newspapers were sold at a certain newsstand today?

1. A total of \(100\) newspapers were sold at the newsstand yesterday, \(10\) fewer than twice the number sold today.

2. The number of newspapers sold at the newsstand yesterday was \(45\) more than the number sold today.

The OA is A

Let the number of newspapers sold today be \(t\) and yesterday be \(y\).
Question: \(t=?\)

From statement 1, we have
\(y = 100\);
Also, \(y = 2t-10\);
\(\Rightarrow 100 = 2t-10\);
\(2t = 110 \Rightarrow t = 55\)
Sufficient. \(\Large{\color{green}\checkmark}\)

From statement 2, we have
\(y = t + 45\)
Not sufficient because of \(2\) variables in the statement. \(\Large{\color{red}\chi}\)

Therefore, A