# What will be The Ratio of Their Surface Sreas?

The ratio of the diameters of two spheres is 3 : 5. What will be the ratio of their surface areas?

- 9: 10
- 3: 5
- 27:125
- 9:25

**Answer: (4) 9: 25**

**Explanation:-
**The ratio of the diameters of two spheres = 3: 5

Then, the ratio of the radius of two spheres = 3/2: 5/2

Formula-

The surface area of the sphere = 4 Pai r^{2}

Then, the ratio of two sphere surface area = 4 Pai (3/2)^{2}/4 Pai (5/2)^{2}

= (3)^{2}: (5)^{2}

= 9: 25

Hence, the answer is (4) 9: 25.