Question : The number of lead balls, each 3 cm in diameter, that can be made from a solid lead sphere of diameter 42 cm is:
Option 1: 2744
Option 2: 4722
Option 3: 7244
Option 4: 2742
Latest: SSC CGL preparation tips to crack the exam
Don't Miss: SSC CGL complete guide
New: Unlock 10% OFF on PTE Academic. Use Code: 'C360SPL10'
Correct Answer: 2744
Solution : Given: A solid lead sphere of diametre 42 cm. The radius of a solid sphere is 21 cm. The radius of a small sphere = $\frac{3}{2}$ = 1.5 cm. The volume of the sphere of radius $r$ is $\frac{4}{3}\pi r^3$. Let $x$ be the total number of lead balls that can be made. According to the question, ⇒ $\frac{4}{3}\times\pi \times(21)^3=x\times\frac{4}{3}\times\pi \times(1.5)^3$ ⇒ $x=\frac{21\times 21\times 21\times 1000}{15\times 15\times 15}=7\times 7\times 7\times 2\times 2\times 2=2744$ Hence, the correct answer is 2744.
Candidates can download this ebook to know all about SSC CGL.
Answer Key | Eligibility | Application | Selection Process | Preparation Tips | Result | Admit Card
Question : How many spherical lead shots each of diameter 8.4 cm can be obtained from a rectangular solid of lead with dimensions 88 cm, 63 cm, and 42 cm?(Take $\left.\pi=\frac{22}{7}\right)$
Question : The number of solid spheres, each of diameter 6 cm, that could be moulded to form a solid metal cylinder of height 90 cm and diameter 4 cm is:
Question : A thousand solid metallic spheres of 6 cm diameter each are melted and recast into a new solid sphere. The diameter of the new sphere (in cm) is:
Question : A solid cone of height 42 cm with a diameter of its base of 42 cm is cut out from a wooden solid sphere of radius 24 cm. Find the percentage of wood wasted correct to two places of decimal.
Question : A spherical ball of lead, 3 cm in diameter, is melted and recast into three spherical balls. The diameters of two of these balls are $\frac{3}{2}$ cm and 2 cm, respectively. Find the diameter of the third ball.
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile