KnowledgeBoat Logo
|

Mathematics

Ritu has a Recurring Deposit Account in a bank and deposits ₹ 80 per month for 18 months. Find the rate of interest paid by the bank if the maturity value of this account is ₹ 1554.

Banking

47 Likes

Answer

Let the rate of interest be x%.

Given,

P = ₹ 80, n = 18 months and r = x%.

I = P×n(n+1)2×12×r100P \times \dfrac{n(n + 1)}{2 \times 12} \times \dfrac{r}{100}

I=80×18×192×12×x100=20×57x100=57x5I = 80 \times \dfrac{18 \times 19}{2 \times 12} \times \dfrac{x}{100} \\[1em] = 20 \times \dfrac{57x}{100} \\[1em] = \dfrac{57x}{5}

Maturity value = Sum deposited + Interest

⇒1554=80×18+57x5⇒1554=1440+57x5⇒114=57x5⇒x=114×557⇒x=10.\Rightarrow 1554 = 80 \times 18 + \dfrac{57x}{5} \\[1em] \Rightarrow 1554 = 1440 + \dfrac{57x}{5} \\[1em] \Rightarrow 114 = \dfrac{57x}{5} \\[1em] \Rightarrow x = \dfrac{114 \times 5}{57} \\[1em] \Rightarrow x = 10.

Hence, rate of interest = 10% per annum.

Answered By

21 Likes

Related Questions