An article having marked price, Rs900, was sold for Rs648 after two successive discounts. The first discount was 20%. What was the percentage rate of the second discount?
एक वस्तु, जिसका अंकित मूल्य 900 रुपये था, दो क्रमिक छूट के बाद 648 रुपये में बेची गयी | पहली छूट 20% की थी | दूसरी छूट की प्रतिशत दर क्या थी?

Options

A. 5
B. 15
C. 10
D. 12.5