# Important Practical Tips for Transport Costing Problems
These conventions are very commonly used in CA Inter questions — keep them at your fingertips.
## 1. Two-Way Journey Convention
In most bus or truck-based questions, a journey is a two-way journey (going and coming back).
## 2. 'One Trip' Meaning
When a question says the truck or bus makes one trip, it means one round journey (to and fro).
## 3. Occupancy
Occupancy means the percentage of seats that are actually filled.
$$\text{No. of passengers} = \text{Total seats} \times \text{Occupancy \%}$$
## 4. Default Occupancy
If nothing is mentioned about occupancy, assume 100% occupancy.
## 5. Different Occupancy on Inward vs Outward
A question can specify different occupancy rates for the onward (going) and inward (coming) legs. Calculate them separately.
## 6. 'Takings'
Takings means sales revenue (the total amount collected from passengers/customers).
## 7. Buses Down for Repairs
If the question says there are 20 buses and on average 10% are down for repairs, do calculations for the operational buses only, i.e., 18 buses.
$$\text{Operational buses} = \text{Total buses} \times (1 - \text{Down \%})$$