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