Question

Find the amount and interest on Rs.24000 for 9 months, being given that interest is compounded quarterly at the rate of 20 paisa a rupee per month.

Answer 1

@ganeshie8 sir plz help :)

Answer 2

we can use this formula whenever we need to work out 'compounded' interest :

\(A = P(1+\frac{r}{n})^{nt} \)

A = amount of money accumulated after n years, including interest.
P = principal amount (the initial amount you borrow or deposit)
r = annual rate of interest (as a decimal)
t = number of years the amount is deposited or borrowed for.
n = number of times the interest is compounded per year

Answer 3

sir can u give me long step method it's compulsory :)

Answer 4

ha

Answer 5

like the one we worked out earlier problem ?

Answer 6

no, i mean finding C.I through Simple interest of one one year

Answer 7

..... rate of 20 paisa a rupee per month.

here we're given SI of one month, is that right

Answer 8

like if we r said to find the C.I of 3 years at the rate of 8%p.a. then finding the S.I. o 1 yr & then find amount

Answer 9

i don't know :(

Answer 10

i get u,

here its not for one year thats given, its for 1 month as it says '20 paisa a rupee per month'

Answer 11

yeah !

Answer 12

since there are 12 months in a year, the rate per year would be ?

Answer 13

1.20 times 12 ?

Answer 14

20 paisa a rupee per month =
12 x 20 paisa a rupee per year =
3 x 20 paisa a rupee per quarter.

Answer 15

ya !

Answer 16

all 3 are same ok, we will take the last one as we are dealing with quarters

Answer 17

k!

Answer 18

every quarter, 3 x 20 = 60 paisa for every rupee is added as interest. which is nothing but 60% rate per quarter

Answer 19

60 paisa per 1 rupee = 60%

Answer 20

make sure its clear :)

Answer 21

i don't gt it surely

Answer 22

every quarter, 3 x 20 = 60 paisa for every rupee is added as interest.

Answer 23

that statement is clear right ?

Answer 24

ya !

Answer 25

60 paisa for every rupee is what percent ?

Answer 26

us this :
1 rupee = 100 paisa

Answer 27

60/100 times 100

Answer 28

thats right !!

Answer 29

60 %

Answer 30

so, 60% is our quarterly rate.

Answer 31

lets work out the rest now

Answer 32

ok !

Answer 33

Rs.24000 for 9 months

Answer 34

9 months = 3 quarters

=> they're calculating interest 3 times.

Answer 35

yes !

Answer 36

total amount with interest =
\(A(1+r)^n\)

r = 60% = 60/100 = 6/10 = 3/5
n = 3

Answer 37

\(24,000(1+\frac{3}{5})^3\)
= ?

Answer 38

\[24000\left( \frac{8 \times 8 \times 8}{5 \times 5 \times 5} \right)\]\[{24000 \times 512 \over125}=98304\]

Answer 39

perfect ! so that the amount including interest.

Answer 40

yes !

Answer 41

find out the interest component by subtracting the initial money 24,000

Answer 42

74,304

Answer 43

so whats the lesson.... ? compound interest is really very very nasty ! we started with 24,000 and in just 9 months, we are forced to pay interest of 74,304 !!!