railway RRB NTPC Mock Test Series 2024-25 (CBT 1 + CBT 2) Quantitative Aptitude Mensuration Solid Figures
The radius of a spherical balloon increases from 5 cm to 10 cm when more air is pumped into it. The ratio of the surface area of the original balloon and that of the inflated balloon is:
1
1 ∶ 2
2
1 ∶ 8
3
1 ∶ 4
4
2 ∶ 1