Question

selling price of a card board is ₹640.if the profit made by the shopkeeper is 20%,find the cost price of the card board​

Answer 1

GIVEN:-

SP of a Card Board = Rs. 640

Profit% = 20%

To Find:-

Cost price.

SOLUTION:-

We know that,

SP = (1 + Profit%) × CP

According to the question,

$\large\Longrightarrow{\sf{SP = (1 + Profit\%) \times CP}}$

By putting the values,

$\large\Longrightarrow{\sf{640 = (1+ 20\%) \times CP}}$

$\large\Longrightarrow{\sf{640 = (1 + \frac{20}{100}) \times CP}}$

$\large\Longrightarrow{\sf{640 = (1+ \frac{1}{5}) \times CP}}$

$\large\Longrightarrow{\sf{640= (\frac{5+1}{5}) \times CP}}$

$\large\Longrightarrow{\sf{640\times\:5= 6</p><p> \times CP}}$

$\large\Longrightarrow{\sf{3200=6</p><p> \times CP}}$

$\large\Longrightarrow{\sf{\frac{3200}{6}= CP}}$

$\large\blue\therefore\boxed{\sf{\blue{CP = Rs.\: 533.3}}}$

• Now let's verify it:-

We know Profit = SP - CP

So,

=> Profit = Rs. (640-533.3)

=> Profit = Rs. 106.7

Now,

$\large\Longrightarrow{\sf{Profit\% = \frac{profit}{CP}\times100}}$

$\large\Longrightarrow{\sf{20 = \frac{106.7}{533.3}\times100}}$

$\large\Longrightarrow{\sf{20= 0.20\times100}}$

$\large\Longrightarrow{\sf{20= 20}}$

$\large\therefore\boxed{\sf{LHS= RHS}}$

$\huge\pink\therefore\boxed{\sf{\pink{CP = Rs. \:533.3}}}$