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

Answer: Option C

Explanation:

Let the new S.P. be x, then.
(100 - loss%):(1st S.P.) = (100 + gain%):(2nd S.P.)

\begin{aligned}
=>\left( \frac{95}{1140} = \frac{105}{x} \right) \\

=> x = 1260
\end{aligned}

Answer: Option B

Explanation:

Let the Cost price of article is Rs. x

Required ratio =
\begin{aligned}
\frac{104\% \text{ of } x}{106\% \text{ of } x} \\
= \frac{104}{106} = \frac{52}{53} = 52:53
\end{aligned}

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 D

Explanation:

Gain % = (164.36*100/2400) = 6.84 % = 7% approx