Question:
Tick (✓) the correct answer
$\left\{\left(\frac{1}{3}\right)^{-3}-\left(\frac{1}{2}\right)^{-3}\right\} \div\left(\frac{1}{4}\right)^{-3}=?$
(a) $\frac{19}{64}$
(b) $\frac{27}{16}$
(c) $\frac{64}{19}$
(d) $\frac{16}{25}$
Solution:
(a) $\frac{19}{64}$
$\left\{\left(\frac{1}{3}\right)^{-3}-\left(\frac{1}{2}\right)^{-3}\right\} \div\left(\frac{1}{4}\right)^{-3}$
$=\left\{3^{3}-2^{3}\right\} \div 4^{3}$
$=\{27-8\} \div 64$
$=19 \div 64$
$=\frac{19}{64}$