Pam is preparing for a trip to the Philippines. She has set aside money for everything that she needs to have, but there are several other items which, while not strictly necessary, she would like to take with her. The following table shows the money that Pam has already spent or allocated, with prices listed in Philippine pesos (P). Expense Cost (P) Transportation 10,804 Hostel 9,773 Food budget 11,229 Sightseeing budget 24,615 Pam’s total budget is P 77,500.Which of the following additional items can Pam afford? I. brand-new walking shoes, P 6,865 II. ticket upgrade to first class, P 15,149 III. electronic Tagalog/English dictionary, P 13,255

The answer is either I and III, or just II.
From the table that shows the money that Pam has already allocated, her current total expenses is the sum of the costs:
     total expenses = Transportation + Hostel + Food budget + Sightseeing budget
                               = 10,804 + 9,773 + 11,229 + 24,615 
                               = 56421 pesos
Subtracting this total expenses to her total budget is her extra budget:
     extra budget = total expenses - total budget
                            = 77500 - 56421 
                            = 21079 pesos 
This means she can afford anything that is below or that sums up to her extra budget. Therefore, she can afford a brand-new walking shoes plus an electronic Tagalog/English dictionary: 6865 + 13255 = 20120. Or she can opt to chose a ticket upgrade to first class alone.