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  1. A sum of money is invested at 20% compound interest (compounded annually). It would fetch Rs. 723 more in 2 years if interest is compounded half yearly. The sum is
    1. Rs.15,000
    2. Rs.30,000
    3. Rs.20,000
    4. Rs.7,500
Correct Option: B

Let the principal be Rs. P.
When the interest is compounded annually,

C.I. = P 1 +
R
T − 1
100

C.I. = P 1 +
20
2 − 1
100

C.I. = P
6
2 − 1
5

C.I. = P
36
− 1
25

C.I. = Rs.
11P
25

When the interest is compounded half–yearly,
C.I. = P 1 +
10
4 − 1
100

C.I. = P
11
4 − 1
10

C.I. = P
14641
− 1
10000

C.I. = Rs.
4641P
10000

From the question ,
∴ 
4641P
11P
= 723
1000025
⇒ 
4641P − 4400P
= 723
10000
⇒ 
241P
= 723
10000

⇒ P =
723 × 10000
= Rs. 30000
241



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