(a) a company that makes plastic utensils is looking at how the price it charges for a knife affects the number of knives it sells per week. which is the dependent variable? number of knives sold per weekprice of a knife(b) the cost of a want-ad in a newspaper increases with the length of the ad. for example, in one newspaper, a want-ad costs $50 plus $3 per word. which is the independent variable in this relationship? length of want-adcost of want-ad(c) a function tells how to compute the output r when the input c is given. which is the dependent variable for this function? rc