Question

Can someone help me with this problem ?

Answer 1

For this, we have to look at ratios between the prices.
so, for A, its $350 for 100 copies
if we take 350/100, you get that one copy is $3.50

using this info, we can solve for 40 papers. 40*3.5 is 140, so it would actually cost 140 dollars for 40 papers

now B.
150/40 is $3.75, so one copy is 3.75
so 100 copies. that would be 3.75*100 which is 375 for 100 copies
 
 

Answer 2

This is the table=
              A             B
1           3.5          3.75  
40          140        150
100        350        375

so more cheaper is printer A