Answer:
The percentage increase in the production cost of the printer is 3%.
Step-by-step explanation:
We are given that the production of a printer consists of the cost of raw material at 100 dollars the cost of overheads at 80$ and wages at 120$.
Also, the cost of raw materials and overheads are increased by 11% and 20% respectively while wages are decreased by 15%.
Cost of raw material = $100
Cost of overheads = $80
Cost of wages = $120
So, the total cost of the printer = $100 + $80 + $120 
                                                    = $300
Now, the increase in the cost of raw material = $100 + 11% of $100
                                                                            =  
 
                                                                            = $100 + $11 = $111
The increase in the cost of overheads = $80 + 20% of $80
                                                                 =  
 
                                                                 = $80 + $16 = $96
The decrease in the cost of wages = $120 - 15% of $120
                                                           =  
 
                                                           = $120 - $18 = $102
So, the new cost of a printer = $111 + $96 + $102 = $309 
Now, the percentage increase in the production cost of the printer is given by;
       % increase =   
 
                          =  
                          =  3%
Hence, the percentage increase in the production cost of the printer is 3%.