Question

Choose the correct Set-builder representation of the interval $(4,12)$.

• A. $\{p:p\in R,4\le p<12\}$
• B. $\{p:p\in R,4\le p\le 12\}$
• C. $\{p:p\in R,4<p<12\}$
• D. $\{p:p\in R,4<p\le 12\}$

Answer 1

The correct option is C $\{p:p\in R,4<p<12\}$

Open Intervals on both extremes of an interval indicates that none of them are actually included in the interval. Hence, the correct option is $\{p:p\in R,4<p<12\}$.