Concept:The difference in compound interest arises from the compounding frequency.Explanation:Let the principal be P.Yearly compounding at 20% p.a. for 2 years:Amount = P(1+0.20)2=1.44PCI yearly = 1.44P−P=0.44PHalf-yearly compounding at 10% per half-year for 4 half-years:Amount = P(1+0.10)4=1.4641PCI half-yearly = 1.4641P−P=0.4641PDifference = 0.4641P−0.44P=0.0241P=482So P=0.0241482​=20000Answer:₹20,000