The difference between simple interest and compound interest at the same rate for Rs.5000 for 2 years is Rs. 72. The rate of interest is?

A. 10 %
B. 12 %
C. 6 %
D. 8 %
Explanation:
5000 × (1 +R/100) 2 – 5000 –(10000R/100)= 72
=> 5000 [(1 + R/100) 2 – 1 – R/50] = 72
=> 1 + R2/100 + 2R/100 – 1 – R/50 = 72/5000
=> R2 = (72/5000 × 10000) = 144 or R =12%