Question 1117688
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Simple interest on Rs 600 for 4 years at the rate of 5% is  Rs 600*0.05*4 = Rs 120.


Simple interest on Rs 600 for 4 years at the rate of 10% is  Rs 600*0.1*4 = Rs 240.


The difference (the value under the question) is  Rs 240 - Rs 120 = Rs 120.
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Solved.