How many spherical bullets of radius 7 cm can be made out from a cube of lead whose edge is 77 cm?
Answer & explanation
Correct answer: option 4
Volume of cube = Total volume of all spherical bullets
⇒ (side)3 = n × \(\frac{4}{3}\) \(\pi \)r3
⇒ (77)3 = n × \(\frac{4}{3}\) \(\pi \) × 73
⇒ (7)3 × (11)3 = n × \(\frac{4}{3}\) × \(\frac{22}{7}\) × 73
⇒ \(\frac{11 × 11 × 11 × 3 × 7}{22 × 4}\)
⇒ n = 317