Question

Ex.7.
A sum of money amounts to Rs. 6400
after 3 years and Rs. 7200 after 5 years
at same rate of interest. What is rate
p.a.?
(A) 7%
(B) 6%
(C) 718%
(D) 8 %​

Answer 1

Step-by-step explanation:

S.I. for 2 years = (amount after 5 years)-(amount after 3 years)

=7200-6400

= 800

S.I. for 1 year= 800/2

= 400

S.I. for 3 years= 400*3

= 1200

Sum= ( amount after 3 years)- ( S.I.for 3 years)

= 6400-1200

= 5200

Now P= 5200

S.I.= 1200

T= 3 years

R= 100*S.I./P*T

= 100*1200/5200*3

=13/100

=0.13%

[ with maths logic, not with your options!!]