400
n
(1.125
20. Rs.40000 was invested at compound interest of 12% compounded semi-
annually. At the end of how many years the amount due will be Rs.53530?
a) 2 years
b) 2 years 6 months
c) 3 years
d) 3 years 6 months
Answers
Answered by
1
Step-by-step explanation:
It is given that
Principal (P) = 40000
Amount (A) = 48620.25
Period (n) = 2 years = 4 half years
Consider rate of interest = r% p.a. =
2
r
% half-yearly
We know that
P
A
=(1+
100
r
)
n
Substituting the values
40000
48620.25
=(1+
100
r/2
)
4
By further calculation
(1+
200
r
)
4
=
(100×40000)
4862025
=
160000
194481
So we get
(1+
200
r
)
4
=(
20
21
)
4
It can be written as
1+
200
r
=
20
21
200
r
=
20
1
By cross multiplication
r=200×
20
1
=10
Hence the rate of interest per annum is 10%.
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