Quantitative Aptitude Ques 1732
Question: A metallic sphere of radius 12 cm is melted into three smaller spheres. If the radii of two smaller spheres are 6 cm and 8 cm, the radius of the third is
Options:
A) 14 cm
B) 16 cm
C) 10 cm
D) 12 cm
Show Answer
Answer:
Correct Answer: C
Solution:
- Let radius of the third sphere be r cm. Then, $ \frac{4}{3}\pi \times {{(12)}^{3}}=\frac{4}{3}\pi \times {{(6)}^{3}}+\frac{4}{3}\pi \times {{(8)}^{3}}+\frac{4}{3}\pi r^{3} $
$ \Rightarrow $ $ {{(12)}^{3}}={{(6)}^{3}}+{{(8)}^{3}}+r^{3} $
$ \Rightarrow $ $ r^{3}=1728-216-512 $
$ \Rightarrow $ $ r^{3}=1000 $
$ \therefore $ $ r=10cm $
BETA
