Original cost: 1.25; markup %: 80

To figure this out, you need to find out what 80% of the cost would be, and add it to the original price.

To find out 80% of 1.25, you need to convert 80(%) to a decimal. You can do this by dividing 80 by 100.

80/100 = 0.8

Add this to the original cost.

1.25 + 0.8 = 2.05

Your total cost in the end would be $2.05

The first thing that you would do would be to make the 80% into a decimal; then you would multiply 0.8 to 1.25 and then add the answer to 1.25.

80/100=0.8
1.25x0.8=1
1.25+1=2.25

The new price would be $2.25

Hope this helps!

In this problem it decreased 20%