ABC26GN1950 · Surds and Indices

Subject: General Aptitude · Chapter: Surds and Indices · Exam: · Marks: · Difficulty:

If $2^{n+4}-2^{n+2}=3$, then $n$ is equal to

(a)0

(b)2

(c)– 1

(d)– 2

Answer

Answer (as printed): D

Explanation

$2^{n+4}-2^{n+2}=3 \Leftrightarrow 2^{n+2}\left(2^{2}-1\right)=3 \Leftrightarrow 2^{n+2}=1=2^{0} \Leftrightarrow n+2=0 \Leftrightarrow n=-2.$

Explanation as extracted from the printed page; notation may be imperfect.