Answer:
$108
Explanation:
The computation of the total profit is shown below:
Given that
1 box = $12
18 boxes = 12×18 = $216
So
Total = 18×65 = 1170 pens
Now Cost price, Cp = $216
Also,
3 = $1
So,
= 378 ÷ 3
= $126
Now
= 1170-378
= 792 pens remaining
4 = $1
So,
792
= 792 ÷ 4
= $198
Now
Total selling price, sp = 126+198 = $324
So finally
Profit = Sp - Cp
= $324 - $216
= $108