# What will be Amount After 20 Years? If

A sum of Rs.12,000 deposited at compound interest becomes double after 5 years. After 20 years it will become:

- Rs. 120000
- Rs. 192000
- Rs. 124000
- Rs. 96000

**Answer: (2) Rs.192000**

**Explanation:-**

**Given-**

Principal = Rs.12,000, Time = 5 years and Rate = R %

Amount is the double of principal,

Then, the amount = 12,000 + 12,000

= Rs.24,000

**Formula-**

**Compound Interest = P [(1 + R/100) ^{t} – 1]**

**Where, P = principal, R = rate, t = time.**

Then,24000 = 12000(1 + R/100)

^{5 }2 = (1 + R/100)

^{5 }2

^{4}= [(1 + R/100)

^{5}]

^{4 }16 = (1 + R/100)

^{20 }16 P = P (1 + R/100)

^{20 }16 x 12000 = 12000 (1 + R/100)

^{20 }192000 = 12000 (1 + R/100)

^{20 }Hence, the answer is (2) Rs.192000.

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