Answer: 2 lamps
Explanation:
Let x = number of good lamps
y = number of broken lamps
x + y = 125
∴ x = 125 - y [1]
Minimum payment = $1365
∴ 12x - 45y ≥ 1365
Subbing [1]
12(125 - y) -45y ≥ 1365
1500 -12y -45y ≥ 1365
-57y ≥ -135
y ≤ 2.37
∴ The maximum number of lamps that can be broken is 2