Question

Price of an article is 400 and sold with discount including 13% vat at 339 find discount rate

Answer 1

To add 13% vat we can multiply by (100%+13%) = 113% = 1.13
To remove 13% vat divide by 1.13
339 / 1.13 = 300 the discounted price.
The amount of discount = 400 - 300 = 100
Discount rate = 100 / 400 = 1/4 = 25%