Question

A certain sum of money at a certain rate of interest becomes Rs. 3420 after 2 years and at the same rate after two and a half years becomes Rs 3525. Find the rate percent per annum.

• A. 8.5%
• B. 8%
• C. 7%
• D. 10%
• E. 11%

Answer 1

The correct option is C 7%

Amount after 2.5 yrs = 3525, after 2 yrs = 3420
So SI for half yr=3525-3420=105, so for 1 yr $SI=105\times 2=210P+2\times SI=3420$
So $P=3420-2\times 210=3000$
So $3000\times r\times \frac{2}{100}=420$