Question

Find the value of $\sqrt[3]{3216}$ + $\sqrt[3]{3\frac{729}{64}}$

• A. 8.12
• B. 8
• C. 8.75
• D. 8.25

Answer 1

The correct option is D

8.25

The given expression is $\sqrt[3]{3216}$ + $\sqrt[3]{3\frac{729}{64}}$

216 = $2\times 2\times 2\times 3\times 3\times 3$ = $2^3\times 3^3$ = $6^3$

729 = $9\times 9\times 9$ = $9^3$

64 = $4\times 4\times 4$ = $4^3$

So, the expression can be written as

$\sqrt[3]{36^3}$ + $\sqrt[3]{3\frac{9^3}{4^3}}$

= 6 + $\frac{9}{4}$

= $\frac{6\times 4+9}{4}$

= $\frac{33}{4}$

= 8.25