Question

Rs.800 is invested in both simple interest and compound interest at the same rate of interest for three years. If the rate of interest is 20%, find the difference between compound interest and simple interest.
1 point
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Answer 1

Answer:

Principal = Rs800

Rate =20%

Time=3years

SI =P×R×T÷100

=800×20×3÷100

=800×60÷100

=48000÷100

=Rs480.

And ,

CI=P[(1+r/100^n)-1]

=800[(1+20/100)^3-1]

=800[1+(1/5)^3-1]

=800[(6/5)^3-1]

=800[216-125/125]

=800×91/125

=800×0.728

=Rs582.40

Thus, difference=CI-SI

=582.40-480

=Rs102.40.

Answer 2

Answer:

Difference between S.I and C.I is 102.4 rupees.

Step-by-step explanation:

Given principle is Rs800 and time is 3 years and rate of interest is 20%.

Simple interest:

We know Simple interest =$\frac{prt}{100}$

Where

$p =$Principle

$r =$Rate of interest

$t =$time

Now Simple interest $= \frac{800 \times 3 \times 20}{100} = 8 \times 3 \times 20 = 480 \: rupees$

Compound interest:

Amount $= p {(1 + \frac{r}{100} )}^{t}$

$= 800( {1 + \frac{20}{100} })^{3} = 800 \times \frac{6}{5} \times \frac{6}{5} \times \frac{6}{5} = 1382.4 \: rupees$

So CI is $(1382.4 - 800) = 582.4$ rupees

Now difference between S.I and C.I is

$(582.4 - 480) = 102.4 \: rupees$