Question

62. In how many years will the principal be double at 9.6 p.c.p.a. simple interest?

(Select two correct alternatives.).
the answer is 125 months and 10 years 5 months but how pls solve my question ​

Answer 1

Answer:

Factorize: x^2-3+1/x^2

Answer 2

$\huge{ \underline{ \overline{ \mid{ \mathfrak{ \purple{ \: \: ANSWER \: \: } \mid}}}}}$

$\bold{ \underline{ \: \: Given \: : \mapsto}} \\ \\ \: \: \: \: \: \: \: \: \: \: \text{Rate \: of \: interest = 9.6\% } \\ \\ </p><p>\text{Let, } \\ \: \: \: \: \: \bold{ The \: \: Principal \: \: amount = P} \\ \\ \bold{ \therefore \: The \: \: total \: \: amount \: \: with \: \: interest = 2P} \\ \\ \bold{ \therefore \: The \: \: amount \: \: of\: \: interest = 2P - P = P} \\ \: \: \: \: \: \: \: \text{i.e. S.I. =P} \\ \\ \\ \text{Suppose,} \\ \: \: \: \: \: \: \: \: \: \: \: \: \bold{The \: \: no. \: \: of \: \: years = n}$

$\underline{ \mathsf{We \: \: know \: \: that,}} \\ \\ \: \: \: \: \bold{S.I. = \frac{ \: Prn \: }{100} } \\ \\ \bold{ \Rightarrow \: P= \frac{P \times 9.6 \times n}{100} } \\ \\ \bold{ \Rightarrow \:100 \times P = P \times 9.6 \times n} \\ \\ \bold{ \Rightarrow \: \frac{100 \times \: \cancel{ P}}{ \cancel{P}} = 9.6 \times n } \\ \\ \bold{ \Rightarrow \:100 = 9.6 \times n } \\ \\ \bold{ \Rightarrow \: n = \frac{100}{9.6} } \\ \\ \bold{ \Rightarrow \:n = 10.41 } \\ \\ \bold{ \: \therefore \: \: n = 10 \: (approx)}$

$\bold{The \: \: no. \: \: of \: \: years = 10 \: \: years \: (approx)}$