Question

Mrs. Mamun invests Rs.250 every month for 2 years in a bank and collects Rs.6312.50 at the end of the term. Find the rate of simple interest paid by the bank on this recurring deposit.

Answer 1

Given that

• Principal(P) for every 2 mount's=Rs.250
• Time(T) =2 year's
• Amount(A) = Rs.6312.50

To Find

• Rate(R) of simple interest paid by the bank.

To Find the Value of Rate we need to find the Simple interest (SI) .

We know that

$\\\overline{\underline{\boxed{\begin{gathered}\implies \sf \purple{ SI=Amount- Principal }\end{gathered} }}}$

• Principal (P) for 1 month= Rs.250
• Principal (P)for 12mount's=Rs.250×12
• Principal (P) for 2 year = Rs.3000×2
• Principal (P) for 2 year = Rs.6000

$\\\\ \text{ \bf{Putting the Value of \gray{principal} and \gray{ amount} in Formula we get}}$

$\sf{SI=6321 - 6000 }$

$\sf{SI=RS.312 }$

Now

• Simple interest (SI)=Rs.312
• principal (P)=6000
• Time=2 year's

We know that

$\\\overline{\underline{\boxed{\begin{gathered}\implies \sf \purple{ SI}= \dfrac{ \purple{Principal×Rate×time}}{ \purple{100}}\end{gathered} }}}$

$\\\\ \sf{→ 312= \dfrac{ 6000×Rate×2}{100}}$

$\sf{→Rate = \dfrac{312 \times 100}{6000 \times 2} }$

$\sf{→Rate = \dfrac{156}{60 } }$

$\sf{→Rate = \dfrac{39}{ 15} }$

$\sf{→Rate = 2.6\% }$

• $\\\\\text{\pink{2.6\%} of Rate paid by}\\\text{ the bank on this recurring deposit.}$