Question

find the Rate per cent per annum if rupees 425 yields rupees 238 interest in 8 years​

Answer 1

$\blue{\bold{\underline{\underline{Answer:}}}}$

$\green{\tt{\therefore{Rate\%=7\%}}}$

$\orange{\bold{\underline{\underline{Step-by-step\:explanation:}}}}$

$\green{\underline \bold{Given :}} \\ \tt:\implies Principal(p) = 425 \: rupees \\ \\ \tt: \implies Simple \: interest(S.I) = 238 \: rupees \\ \\ \tt: \implies Time (t)= 8 \: years \\ \\ \red{\underline \bold{To \: Find :}} \\ \tt: \implies Rate\%(r) = ?$

• According to given question :

$\bold{As \: we \: know \: that} \\ \tt: \implies S.I= \frac{p \times r \times t}{100} \\ \\ \tt: \implies 238 = \frac{425 \times r \times 8}{100} \\ \\ \tt: \implies 238 \times 100 = 3400 \times r \\ \\ \tt: \implies r = \frac{23800}{3400} \\ \\ \green{\tt: \implies r = 7\%} \\ \\ \blue{\bold{Some \: formula \: related \: to \: topic}} \\ \orange{\tt \circ \: A = p + S.I} \\ \\ \orange{\tt \circ \:A = p(1 + \frac{r}{100} )^{t} } \\ \\ \orange{\tt \circ \: C.I = A- p}$

Answer 2

AnswEr:-

Rate of interest = 7% per annum.

$\rule{200}{1}$

Given:-

• Principal (P) = Rs.425
• Time(n) = 8 years.
• Simple interest(SI) = Rs.238

To find:-

• Rate of interest = ?

Solution :-

As we know formula for SI:-

$\star \: {\boxed{\rm{\blue{Simple \: interest (SI) = \dfrac{P \times r \times n }{100} }}}}$

• Plugging values:-

$\dashrightarrow\sf 238 = \dfrac{425 \times r \times 8}{100} \\\\\dashrightarrow\sf 23800 = 3400r \\\\\dashrightarrow\sf r =\cancel{ \dfrac{23800}{3400}} \\\\\dashrightarrow{\underline{\boxed{\textsf{\textbf{r = 7\% }}}}}$

$\therefore\underline{\textsf{Rate of interest ={\textbf{ 7\% p.a. }}}}$