Question

Rs 5000 is deposited at 6 % simple interest. Check if the S.I amount at the end of the every year is in A.P if this an A.P,then find the amount of interest after 18 yrs

Answer 1

:P= 5000₹
:Rate = 6 P.c.P.a
:N= 18 years
.........................
=S.I =P × N ×R÷ 100
...........
=S.I = 5000×6×18÷100
..........
=50×6×18
....
=300×18
........
=5400₹
... ......
= Amount of intrest is 5400₹

Answer 2

Answer:

Yes, the S.I amount at the end of the every year is in AP and  the amount of interest after 18 yrs 5400.

Step-by-step explanation:

Given information: Principal = 5000, Rate of interest = 6%.

Formula for interest:

$I=P+\frac{P\times r\times t}{100}$

Where, P is principal, r is rate of interest, t is time in years.

The S.I amount at the end of first year is

$I_1=\frac{5000\times 6\times 1}{100}=300$

The S.I amount at the end of second ear is

$I_2=\frac{5000\times 6\times 2}{100}=600$

The S.I amount at the end of third year is

$I_3=\frac{5000\times 6\times 3}{100}=900$

The S.I amount at the end of the every year is

$300,600, 900,..$

Here first term is 300 and common difference is 300. So S.I amount at the end of the every year is in AP.

The nth term of an AP is

$a_n=a+(n-1)d$

The amount of interest after 18 yrs

$a_{18}=300+(18-1)(300)$

$a_{18}=300+(17)(300)=5400$

Therefore the amount of interest after 18 yrs 5400.