The difference between simple interest and compound interest of a certain sum of money at 10% per annum for 1 year is ₹180. Then the sum is: (Interest being compound half yearly)

₹72000

Simple interest ⇒ 10% 

Compounded interest ⇒ 5 + 5 + \(\frac{5 × 5}{100}\) ⇒ 10.25 

Diff. b/w C.I & S.I. for two years ⇒ 10.25 - 10% ⇒ 0.25%

ATQ,

0.25 % P = 180

1% P = \(\frac{180}{.25}\)

100 % P = \(\frac{180}{25}\) × 10000

 Principal = Rs.72000