Question Detail

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 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}

1. A producer of tea blends two varieties of tea from two tea gardens one costing Rs 18 per kg and another Rs 20 per kg in the ratio 5 : 3. If he sells the blended variety at Rs 21 per kg, then his gain percent is

Answer: Option A

Explanation:

Suppose he bought 5 kg and 3 kg of tea.
Cost Price = Rs. (5 x 18 + 3 x 20) = Rs. 150.
Selling price = Rs. (8 x 21) = Rs. 168.
Profit = 168 - 150 = 18

So, Profit % = (18/150) * 100 = 12%

2. 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 D

Explanation:

3. A shopkeeper cheats to the extent of 10% while buying and selling, by using false weights. His total gain is.

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}

4. A book was sold for Rs 27.50 with a profit of 10%. If it were sold for Rs. 25.75, then would have been percentage of profit and loss ?

2% Profit
3% Profit
2% Loss
3% Loss

Answer: Option B

Explanation:

Please remember
\begin{aligned}
S.P. = \left( \frac{100+gain\%}{100} * C.P \right)\\
\text{So, C.P. = }\left( \frac{100}{110} * 25.75 \right)\\
\text{When S.P. = 25.75 then } \\
Profit = 25.75 - 25 = Re. 0.75 \\

Profit\% = \frac{0.75}{25} * 100 = 3\%

\end{aligned}

5. The cost price of 20 articles is the same as the selling price of x articles. If the profit is 25% then determine the value of x.

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}