Which among following options are true relating to this question :

Ram sold a card and makes 20% profit out of it, how much profit he actually earned ?

1. Difference between cost price of card and selling price of card is Rs. 40.
2. Selling price of card is 120% of cost price of card.

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 B

Explanation:

Question seems a bit tricky, but it is very simple.
Just calculate all Cost price, then get 150% of CP.

C.P. = 10000 + 5000 + 1000 = 16000

150% of 16000 = 150/100 * 16000 = 24000

Answer: Option C

Explanation:

Whenever we get this type of question, we should have formula in mind that,
Gain% = (gain/cost)*100

Cost = 4700 + 800 = Rs. 5500
S.P. = Rs. 5800

Profit = 5800 - 5500 = 300
\begin{aligned}
Gain\% = \frac{300}{5500}*100 \\
= 5\frac{5}{11}\%
\end{aligned}

Answer: Option D

Explanation:

Hint: Calculate profit percent as

Profit% = (profit/cost) * 100

Answer: Option B

Explanation:

\begin{aligned}
Gain\% = \\ \left( \frac{(100 + \text{common gain}\%)^2}{100} - 100 \right)\% \\
= \left( \frac{(100 + 10)^2}{100} - 100 \right)\% \\
= \left( \frac{12100 - 10000}{100}\right)\% \\
= 21\%

\end{aligned}