ABC26GN1896 · Surds and Indices

Subject: General Aptitude · Chapter: Surds and Indices · Exam: 2009 · Marks: · Difficulty:

$(81)^{4} \div(9)^{5}=$ ?

(a)9 $\frac{3}{2}$

(b)81 $\frac{4}{9}$

(c)729 $\frac{16}{81}$

(d)6561 $\frac{32}{243}$

(e)None of these

Answer

Answer (as printed): C

Explanation

$(81)^{4} \div(9)^{5}=\frac{\left(9^{2}\right)^{4}}{\left(9^{5}\right)}=\frac{9^{(2 \times 4)}}{9^{5}}=\frac{9^{8}}{9^{5}}=9^{(8-5)}=9^{3}=729$.

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