Answer:
His gain percent is 20%
Step-by-step explanation:
In this question, we want to find the percentage gain of the business.
We need the following parameters;
The cost price which is the sum of the amount she bought the goods + the amount spent on transport
Using the values we have in the question;
The cost price will be;
13,600 + 400 = Rs 14,000
The selling price = Rs 16,800
Mathematically the percentage gain will be;
% gain = (selling price- cost price)/selling price * 100%
% gain = (16,800-14,000)/14,000 * 100/1
% gain = 2800/14,000 * 100/1 = 1/5 * 100/1 = 20%
is 
, we know that 
. So,