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

Options

A. 0.085
B. 0.08
C. 0.07
D. 0.1

Answer

C

Explanation

Amount after 2.5 yrs.= 3525, after 2 yrs = 3420
So SI for half yr = 3525 - 3420 = 105,
So for 1 yr SI = ` 105 xx 2 = 210`
` P + 2 xx SL = 3420`
So P = `3420 - 2 xx 210 = 3000`
So, P = 3420 ` - 2 xx 210 = 3000`
So, `3000 xx r xx 2/100 = 420`
r = 7%