A TV is purchased at Rs. 5000 and sold at Rs. 4000, find the lost percent.

Answer: Option D

Explanation:

Let the Cost Price of one article = Rs. 1
CP of x articles = Rs. x
CP of 20 articles = 20
Selling price of x articles = 20

Profit = 25% [Given]

\begin{aligned}
\Rightarrow \left (\dfrac{SP - CP }{CP}\right ) = \dfrac{25}{100} = \dfrac{1}{4}

& \Rightarrow \dfrac{\left(20-x \right )}{x} = \dfrac{1}{4} \\
& \Rightarrow 80 - 4x = x \\
& \Rightarrow 5x = 80 \nonumber \\
& \Rightarrow x = \dfrac{80}{5} = 16 \\

\end{aligned}

Answer: Option C

Explanation:

Let original Cost price is x
Its Selling price = 105/100 * x = 21x/20
New Cost price = 95/100 * x = 19x/20
New Selling price = 110/100 * 19x/20 = 209x/200
[(21x/20) - (209x/200)] = 1

=> x = 200

Answer: Option B

Explanation:

We know, C.P. = 5000
S.P. = 4000
Loss = 5000 - 4000 = 1000
\begin{aligned}
Loss\% = \left( \frac{Loss}{Cost} * 100 \right)\% \\
= \left( \frac{1000}{5000} * 100 \right)\% = 20\%
\end{aligned}

Answer: Option C

Explanation:

We need to get the Total selling price to solve this question. Because after getting selling price we can get profit or loss, then we can calculate profit% or loss%

So lets solve this:

Price Received by selling one fourth of the material at a loss of 20% =
(1/4) * 600 * (80/100) = Rs. 120

Price Received by remaining material at a gain of 10% =
(3/4) * 600 * (110/100) = Rs. 495 [Note: 1-(1/4) = 3/4]

Total Selling Price = 120 + 465 = Rs. 615

Profit = 615 - 600 = 15

\begin{aligned}
Profit\% = \left( \frac{Gain}{Cost} * 100 \right)\% \\
= \left( \frac{15}{600} * 100 \right)\% \\
= \frac{5}{2}\% = 2\frac{1}{2}\%
\end{aligned}

Answer: Option B

Explanation:

We Know,

\begin{aligned}
S.P. = \left( \frac{100+gain\%}{100} * C.P \right)\\
=> C.P. = \frac{100}{122.50}* 392 \\
= 320 \\

Profit = 392 -320 = Rs 72
\end{aligned}