Question

The compound interest on₹ 8000 at 10% p.a for 2 years is:​

Answer 1

A trader by selling one kind of tea at 380/kg. makes a loss of 20% and makes a pri

25%by selling another kind of tea at 200/kg. At what ratio these two types of tensi

be mixed so that by selling it at 150/kg. the profit would be 25%?.Let mass of one kind of tea x kg be mixed with another kind of tea mass y kg

SP of x kg tea = Rs 80x

Loss = (CP - SP)/CP

0•2 CP = CP - 80x

0•8CP = 80x. Or CP = 100x

Similarly

Profit = (SP - CP)/CP

0•25CP = 200y - CP

1•25CP = 200y . Or CP = 20000y/125 =160y

Total CP of x and y kg of tea = 100x + 160y

SP of x and y kg of tea = (x + y )×150

Profit = (SP - CP)/CP

0•25 = {(x + y )150 - (100x + 160y)}/(100x +160y)

0•25(100x + 160y) = (50x - 10y)

25x + 40y = 50x - 10y

25x = 50y

x/y = 2/1

Answer 2

Given :-

• Principal = ₹8000.
• Rate per annum = 10%.
• Time = 2 Years.

To Find :-

• Compound Interest.

Solution :-

Formula Used :-

$\boxed{\sf{A = P {\bigg(1 + \frac{r}{100}\bigg) }^{n}}}$

Substitute the Values.

$\sf\dashrightarrow{\sf{A = 8000 {\bigg(1 + \frac{10}{100}\bigg) }^{2}}}$

$\sf\dashrightarrow{\sf{A = 8000 {\bigg(\frac{100 + 10}{100}\bigg) }^{2}}}$

$\sf\dashrightarrow{\sf{A = 8000 {\bigg(\frac{110}{100}\bigg) }^{2}}}$

$\sf\dashrightarrow{\sf{A = 8000 {\bigg(\frac{11}{10}\bigg) }^{2}}}$

$\sf\dashrightarrow{\sf{A = 8000 \times {\frac{11}{10} \times \frac{11}{10} }}}$

$\sf\dashrightarrow{\sf{A = 80 \times 11 \times 11}}$

$\sf\dashrightarrow\boxed{\red{\sf{A = Rs. \: 9680 }}}$

Formula For C.I. :-

C.I. = Amount – Principal.

➨ C.I. = ₹9680 — ₹8000.

➨ C.I. = ₹1680.

Therefore,

Compound Interest = ₹1680.