# Area 8

### From Homeworkwiki

**Problem: The radii of two circular silver plates of the same thickness are in the ratio 3:4.**

**If the bigger plate costs $ 656, how much will the smaller plate cost?**

**Solution:** Since, the thickness remains the same, the cost of the plates are proportional to the area of the plates.

The areas of the plates are in the ratio 3^{2}: 4^{2}

[ since their radii are in the ratio 3: 4]

=> The smaller plate will cost 656 X 9/16 = $ 369