Answer :
Let her initial cost be 100. Hence with 50% profit SP is 150.
Now due to additional investment, cost increases to 125 but SP remains at 150. Therefore new profit % is 25/125×100 =20% is the new Profit %.
Hence decrease in Profit % = 50- 20 = 30%.
Now due to additional investment, cost increases to 125 but SP remains at 150. Therefore new profit % is 25/125×100 =20% is the new Profit %.
Hence decrease in Profit % = 50- 20 = 30%.