Question

A certain sum of money amounts to Rs5292 in 2years and Rs5556.50 in 3years, interest being compounded annually, Find the rate percent and the sum

Answer 1

RS. 5556.50 - RS.5292 = RS. 264.60 (S.I for 1 yr)
P= 5292 ; T= 1 yr ; SI= RS. 264.60 ; R= ? 
SI= PRT/100
264.60 = (5292 x R x 1) / 100
264.60 x 100 = 5292 x R
26460 = 5292 x R
R= 26460 / 5292 
R= 5%
 To find the sum:
Let P be 'p' , A be rs 5292 , T be 2yrs , R= 5% p.a 
5292= P(1+5/100)^2
5292= p x 105/100 x 105/100
5292= p x 21/20 x 21/20
5292x400 = p x 21x21
2116800= p x 441
p = 2116800/441
p= RS.4800
therefore, rate= 5% and sum= Rs.4800