ABC Office Supply offers an electric typewriter for $129.95. If ABC received a 15% markup on cost by selling the typewriter at this price, what was the cost of the typewriter to ABC?

Assume that C is the original cost of the typewriter

 then,  they got 15% as markup plan.

 now,c+(c*.15)=129.95$

        c+.15c=129.95

        1.15c=129.95

              c=113$

the actual cost of the typewriter is , 113$

given cost of the typewriter = $129.95 

markup offer = 15%

15% markup on 129.95 = 15 x 129.95 / 100

                                  =19.5

Now original cost  = 129.95 - 19.5 = $ 110.5