Answer:
The question is incomplete; the complete question is given below.
                         Selling Price per unit	Variable  cost per unit
Product                                     $                                  $
Snowboards                           20.00                       170.00
Skis                                  400.00                          225.00
Poles                                      50.00                 20.00
Salvador's contribution margin is  46.2%
Explanation:
Contribution is the amount generated from the sales of a product to cover part of the total fixed cost. 
Contribution is an important concept in decision making because it helps to determine the profitability of individual products where a set of products benefit from the same fixed cost. <em>it </em><em>helps in prioritizing the allocation of resources to different products based on their profitability</em> .
Contribution per unit = Selling price per unit- variable cost per unit
Total contribution= Contribution per unit * units sold
Contribution margin ration: The proportion of sales realised as contribution is known as contribution margin ratio (CMR) . It represents the amount generated as contribution from every one dollar worth of sales.  A 60% margin means that $60 is made as contribution from evry sales of $100, for example. 
It is a calculated as follows:
Single-product scenario: 
C.M.R= contribution per unit/ selling price per unit
Multiple-products scenario:
C.M.R= contribution from a mix / revenue from a mix
We shall use the multiple-products formula
                                          Snowboard                 ski             Poles     Total
                                                    $                             $                $
Selling price                              320                     400                50
variable cost                        <u>    (170)                      (225)              (20)</u>
Contribution per unit (SP-VC)   <u>150                           175                30</u>
Cont from a mix (cont× unit)   1050                       525                 60
Revenue from a mix (SP× unit) 2240                    1200               100
Contribution margin ratio= Cont. from a mix/ Rev from a mix 
                                            = (1050+525+60)/(2240+1200+100)
                                            =(1635 /  3540) × 100
                                             = 46.2 %