Simple and Compound Interest Quiz 1

S.I=pnr/100
p=5000;n=5;r=12
sub and get S.I=3000
amount aft 5 yrs=principle+S.I
=8000

Let Cost Price(C.P) = P
gain% = {(S.P-C.P)/C.P} x 100
25 = {(1540-P)/P} x 100
25/100 = (1540-P)/P
=> P = 4(1540)-4P
=> 5P = 4(1540)
=> P = 1232
So, Cost Price = Rs. 1232

By the problem (p * r * t)/100=1500
or, (5000 * 2.5 * t)/100=1500
which gives t=12 years.

As the rate of interest for both the cases are same

(A1-P)/T1 = (A2-P)/T2

(2500-p)/5=(3000-p)/7
17500 - 7p = 15000 - 5p

p=1250