1. Total cost of the field trip = Total cost of all students + Transportaion cost

Cost per student = 250

Total number of students = 42

Therefore, Total cost of all student = 250 x 42

Total cost of all students = 10500

Given that, Transportaion cost is 5000.

Therefore,

Total cost of the field trip = 10500 + 5000

Total cost of field trip = 15500 Rs.

2. Now, if each student contributes an equal amount to the total cost of 15500 Rs, each student will have to pay,

15500/42 = 369.05

That is, each student will have to approximately pay Rs. 369 so that each student contributes an equal amount towards the total cost of the field trip.