Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
Shamshad Ali buys a scooter for $₹ 22000$. he pays $₹ 4000$ cash and agrees to pay the balance in annual instalment of $₹ 1000$ plus $10 \%$ interest on the unpaid amount. How much will the scooter cost him ?
MathematicsSequences and Series
Solution:
2997 Upvotes Verified Answer
Total cost of a scooter $=₹ 22000$
Paid cash $=₹ 4000$
Balance $=$ ₹ 18000
Number of instalments@ ₹1000 each =18
Interest on first instalment $=₹ \frac{18000 \times 10 \times 1}{100}$
=₹ 1800
$\therefore$ First instalment $=₹ 1000+1800=₹ 2800$
Interest on second instalment
$=₹ \frac{17000 \times 10 \times 1}{100}=₹ 1700$
$\therefore$ Second instalment $=₹ 1000+1700$
$=₹ 2700$
Interest on third instalment
$=₹\left(\frac{16000 \times 10 \times 1}{100}\right)=₹ 1600$
Third instalment $=₹(1000+1600)=₹ 2600$
$\therefore$ Total amount paid in instalments
$=₹(2800+2700+2600+\ldots \ldots \ldots \ldots+18$ terms $)$
$a=2800, d=-100, n=18$
$\begin{aligned}
S=& \frac{18}{2}[2 \times 2800+(18-1)(-100)] \\
&=9(5600-1700)=9 \times 3900=35100
\end{aligned}$
Scooter with cost him $₹(4000+35100)$ $=₹ 39100$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.