A 15% percent markup means that the typewriter cost was increased by 15%, or 0.15 by moving the decimal 2 places to the left. If the original price was x, and 15% of it is 0.15*x, we can add them up to get 1.15*x=129.95. Dividing both sides by 1.15, we get x=113 dollars
1/3 + 5/6 + 5/12
1.583333333333333
12 because the rest of the numbers are all similar except 12
