We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.More informationAgree
ad

Simple Interest #14

14. A lent $₹5000$ to B for $2$ years and $₹3000$ to C for $4$ years on simple interest at the same rate of interest and received $₹2200$ in all from both of them as interest. What is the rate of interest per annum?
A. $7\%$B. $5\%$
C. $10\%$D. $8\%$

Answer: Option C

Explanation:

Solution 1

Let required rate be R%

Simple interest on $₹5000$ for $2$ years + simple interest on $₹3000$ for $4$ years $=₹2200$

$\Rightarrow \dfrac{5000×\text{R}×2}{100}+\dfrac{3000×\text{R}×4}{100}=2200\\\Rightarrow \text{100R+120R}=2200\\\Rightarrow \text{220R}=2200\\\Rightarrow \text{R}=10$

Solution 2

SI on $₹5000$ for $2$ years + SI on $₹3000$ for $4$ years $=₹2200$
$\Rightarrow$ SI on $₹50$ for $1$ year + SI on $₹30$ for $2$ years $=₹11$
$\Rightarrow$ SI on $₹30$ for $\dfrac{5}{3}$ years + SI on $₹30$ on $2$ years $=₹11$
$\Rightarrow$ SI on $₹30$ for $\dfrac{11}{3}$ years $=₹11$
$\Rightarrow$ SI on $₹30$ for $1$ year $=₹3$
$\Rightarrow$ SI on $₹100$ for $1$ year $=₹10$

Therefore, required rate is $10\%$

Add Your Comment

(use Q&A for new questions)
?
Name
cancel
preview