SSC MTS 2 Aug 2019 Shift 1 Paper

Calculation:
Total small droplets coalesced to form big bubble = 0.1% of $1.728\times {10}^6$
= 1728
Let the radius of big bubble be R mm
⇒ $1728\times \frac{4}{3}\times \mathrm{\pi }\times {\left(\frac{2}{2}\right)}^3=\frac{4}{3}\times \mathrm{\pi }\times {\mathrm{R}}^3$
⇒ ${\mathrm{R}}^3$ = 1728
⇒ R = 12 mm or 1.2 cm
⇒ Diameter = 2 × R = 2 × 1.2 = 2.4 cm