Solution
GivenIn this question, we are given that
• A copy service charges $0.05 per copy for the first 100 copies, $0.04 per copy for the next 100 copies, and $0.03 per copy for all copies thereafter
To findWe need to determine
• The service charge for 350 copies
Approach and Working outWe can deduce a generalised expression for n copies, where n > 200 (here 200 = 100 + 100)
Charge for the first 100 copies = 100 x 0.05 = 5
Charge for the next 100 copies = 100 x 0.04 = 4
• Hence, charge for the first 200 copies = 5 + 4 = 9
For total n (>200) copies,
• Total service charge = 9 + (n – 200) x 0.03
If n = 350, then the total service charge = 9 + (350 – 200) x 0.03 = 9 + 150 x 0.03 = 9 + 4.5 = 13.5
Thus, option E is the correct answer.
Correct Answer: Option E _________________