Practice | Hashtable

1. The volume of a sphere is $2145 \frac{11}{21} c m^{3} .$ Its radius is equal to :

A. 7 cm

B. 8 cm

C. 9 cm

D. None of these

Solution:

\begin{aligned} \frac{4}{3} \times \frac{22}{7} \times r^{3} = \frac{45056}{21} \\ \Rightarrow r^{3} = (\frac{45056}{21} \times \frac{3}{4} \times \frac{7}{22}) \\ \Rightarrow r^{3} = 512 \\ \Rightarrow r = \sqrt[3]{512} \\ \Rightarrow r = 8 c m \end{aligned}

You must login to add comments. Login now.