Question

find the time if ruppess 8000 lent at c.i. at 20 percent amount to 8820; the intrest being compounded half yearly.
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Answer 1

Answer:

1 year

Step-by-step explanation:

Principal (P) = ₹8000

Amount (A) = ₹8820

When compounded half-yearly, the rate is halved and the time is doubled.

Rate (R) = (20÷2)% = 10%

Let the Time be n.

A = P (1 + R/100)ⁿ

=> 8820 = 8000 (1 + 10/100)²ⁿ

=> 8820/8000 = (110/100)²ⁿ

=> 441/400 = (11/10)²ⁿ

=> (21/20)² = (22/20)²ⁿ

=> 2 = 2n

=> n = 1 year