The cost price of 20 articles is the same as the selling price of x articles. If the profit is 25%, find out the value of x

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 C

Explanation:

Let the cost price 1 article = Re 1
Cost price of x articles = x
S.P of x articles = 20

Gain = 20 -x

\begin{aligned}
=> 25 = \left( \frac{20-x}{x} * 100 \right) \\
=> 2000 - 100x = 25 x \\
=> x = 16
\end{aligned}

Answer: Option A

Explanation:

This type of question can be easily and quickly solved as following:

Let at Rs x it can earn 15% pr0fit
85:18700 = 115:x [as, loss = 100 -15, Profit = 100 +15]

x = (18700*115)/85
= Rs.25300

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:

As question states that rate was of pair of articles,

So rate of One article = 37.40/2 = Rs. 18.70

Let Marked price = Rs X
then 85% of X = 18.70

=> X = 1870/85 = 22