Since only one person can finish in first place, one in second, etc., the total number of placers is 12x11x10, or 1320 different ways the 12 racers can finish 1st, 2nd and 3rd....
☺☺☺☺
Its C. Add 3 and 15 which gives you 18. Then move the variable (4x) to the left. Then combine like terms which are the x’s and you should get 3x. Then divide both sides by 3. (18/3 = 6)