please answer my question
Answers
Step-by-step explanation:
Principal (P) = Rs. 640
Amount (A) = Rs. 774.40
Time (n) = 2 years
Rate of interest (R) % = ?
We know that,
\begin{gathered}A = P {(1 + \frac{R}{100} )}^{n} \\ \\ 774.40 = 640 {(1 + \frac{R}{100} )}^{2} \\ \\ 774.40 = 640 {(1 + \frac{R}{100} )}^{2} \\ \\ \frac{774.40}{640} = {(1 + \frac{R}{100} )}^{2} \\ \\ \frac{77440}{640 \times 100} = {(1 + \frac{R}{100} )}^{2} \\ \\ \frac{121}{100} = {(1 + \frac{R}{100} )}^{2} \\ \\ { (\frac{11}{10}) }^{2} = {(1 + \frac{R}{100} )}^{2} \\ \\ \frac{11}{10} = 1 + \frac{r}{100} \\ \\ \frac{11}{10} - 1 = \frac{R}{100 } \\ \\ \frac{11 - 10}{10} = \frac{r}{100} \\ \\ \frac{1}{10 } = \frac{R}{100} \\ \\ \frac{1}{10} \times 100 = r \\ \\ 10 = R\end{gathered}
A=P(1+
100
R
)
n
774.40=640(1+
100
R
)
2
774.40=640(1+
100
R
)
2
640
774.40
=(1+
100
R
)
2
640×100
77440
=(1+
100
R
)
2
100
121
=(1+
100
R
)
2
(
10
11
)
2
=(1+
100
R
)
2
10
11
=1+
100
r
10
11
−1=
100
R
10
11−10
=
100
r
10
1
=
100
R
10
1
×100=r
10=R