A calculator with an original price of $13,575 was sold at $11,267.25.
How much was the discount? Solve for the rate of discount.
Please show your solution. Thanks!

An appliance center pays $25,990 to its supplier for a sala set, then sell it
with a markup rate of 10%. How much is the markup price? How much is the
selling price?
Please show your solution. Thanks!​