Question

Find the interest and the amount on:
(i) Rs. 750 in 3 years 4 months at 10% per annum
(ii) Rs. 5000 at 8% per year from 23rd December 2011 to 29th july 2012.
(iii) Rs. 2600 in 2 years 3 months at 1% per month.
(iv) Rs. 2600 in 2 years 3 months at 1% per month.

Answer 1

Given P= Rs. 750
Time(T)=3 $\frac{4}{12}=3\frac{1}{3}$
$=\frac{10}{3}$ years
Rate(R) =10% $\therefore$ Interest(I)= $\frac{PTR}{100}=\frac{750\times 10\times \frac{10}{3}}{100}$
$=\frac{250\times 10\times 10}{100}=Rs.250$ $\therefore$ Amount(A)= P+1= Rs. 750 + Rs. 250= Rs. 1000
Principle(P)=Rs.5000
Rate(R)=8%p.a.
Time(T)=23 December 2011 to 29 July 2012
Dec. Jan. Feb. Mar. Apr. May. Jun. Jul
8 31 29 31 30 31 30 29
Total 219 days =$\frac{219}{365}$ years
$\therefore$ interest= $\frac{PTR}{100}=\frac{5000\times 8\times 219}{100\times 365}$
$=10\times 8\times 3$
$\therefore$ Amount=P+1=Rs. 5000 +240 = Rs. 5240
(iii) Here P= 2600
Time(T)=2 years 3 months= 27 months
Rate(R)=1% per month $\therefore$ Interest= $\frac{P\times T\times R}{100}=\frac{2600\times 27\times 1}{100}$
$=26\times 27=Rs.702$
$\therefore$ Amount=Rs. (2600+702)=Rs. 3302
(iv) Here P= Rs. 4000, Time(T) = $1\frac{1}{3}$ year
$=1year+\frac{12}{3}months=16months$
Rate(R)=2 paise per rupee per month=2% per month
$\therefore$ Interest(I)= $\frac{PTR}{100}=\frac{4000\times 2\times 16}{100}$
$=40\times 32=Rs.1280$
$\therefore$ Amount(A) =P+1= Rs. 4000+Rs. 1280=Rs. 5280