1). 212). 283). 354). 19

1.	1). 212). 283). 354). 19
Answer» FIRST Case: PRINCIPAL AMOUNT = P Amount = 2P Time = 7 years Rate = r% ⇒ $(2P = P \times {\left( {1 + \frac{r}{{100}}} \right)^7})$ ⇒ 2 = (1 + 0.01r)⁷ ⇒ $({2^{\frac{1}{7}}} = 1 + 0.01r)$----(1) Second Case: Principal = P Amount = 16P Time = t Rate = r% ⇒ $(16P = P \times {\left( {1 + 0.01r} \right)^t})$ ⇒ $(16 = {\left( {1 + 0.01r} \right)^t})$ From EQ. (1), we get ⇒ $({2^4} = {\left( {{2^{\frac{1}{7}}}} \right)^t})$ ⇒ 4 = t/7 ⇒ t = 4 × 7 = 28 ∴ Sum will be 16 times after 28 years.

Answer»

FIRST Case:

Amount = 2P

Time = 7 years

Rate = r%

⇒ $(2P = P \times {\left( {1 + \frac{r}{{100}}} \right)^7})$

⇒ 2 = (1 + 0.01r)⁷

⇒ $({2^{\frac{1}{7}}} = 1 + 0.01r)$----(1)

Second Case:

Principal = P

Amount = 16P

Time = t

Rate = r%

⇒ $(16P = P \times {\left( {1 + 0.01r} \right)^t})$

⇒ $(16 = {\left( {1 + 0.01r} \right)^t})$

From EQ. (1), we get

⇒ $({2^4} = {\left( {{2^{\frac{1}{7}}}} \right)^t})$

⇒ 4 = t/7 ⇒ t = 4 × 7 = 28

∴ Sum will be 16 times after 28 years.

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