We have been provided with the information that

100-watt light bulbs is $12, 100.00. so fixed cost $ 12,100

If the cost of producing each twin-pack of light bulbs is $0.60 so variable cost is 0.60$ each

each twin-pack sells for $1.15,

Fixed Cost=       12,100

Variable Cost= .6x

So, the Cost function will be:

C(x)= 0.6 x +12,100

where x is the number of units produced.

Revenue fuction is as follow

R(x)= 1.15 x

where R stands for revrnue and x the total # of units sold

Profit Function is as follow

P(x)= R(x) – C(x)

where P is profit. Substituting.

P(x)= [1.15x]-[0.6x+12,100]

P(x)= 0.55x-12,100