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

Answer: Option A

Explanation:

Please note in this type of questions, get the value of 1 kg to solve this question, lets solve it.

C.P. of 1 Kg = 420/70 = Rs. 6
Selling Price = 6.50
Gain = Rs. 0.50

\begin{aligned}
Gain\% = \frac{.50}{6}*100 \\
= 8\frac{1}{3}\%
\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

Answer: Option C

Explanation:

From the question it is clear that, Gain is 20%
From 1, it is clear that S.P. - C.P. = 40, so it is sufficient to get answer.
While 2 is not sufficient to get answer.

Answer: Option D

Explanation:

So we have C.P. = 27.50
S.P. = 28.60

Gain = 28.60 - 27.50 = Rs. 1.10

\begin{aligned}
Gain\% = \left( \frac{Gain}{Cost} * 100 \right)\% \\
= \left( \frac{1.10}{27.50} * 100 \right)\% = 4\%
\end{aligned}

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}