Respuesta :

20 = 10 x 10 = 100 x 2 = 200 

40 = 200x2 = 400

60 = 200x3 = 600
Hey there,
1 hour = $20
20 hours = $ 20 x 20
               = $400
40 hours = $20 x 40
               = $800
60 hours = $20 x 60
               = $1,200

Hope this helps :))

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