A certain sum amounts to ₹3,640 in 2 years and ₹4,060 in 8 years at simple interest. Find the approximate rate percentage per annum ?
Answer & explanation
Correct answer: option 2
Amount in 2 years = Rs.3640
Amount in 8 years = Rs.4060
S.I in 6 years = 4060 - 3640 = Rs.420
S.I. in 1 year = \(\frac{420}{6}\) = Rs.70
S.I. in 2 years = Rs.140
Principal = 3640 - 140 = Rs.3500
∴ Rate% = \(\frac{Interest}{Principal}\) × 100
= \(\frac{70}{3500}\) × 100
= 2%