Final answer:
The initial payment needed when booking an adventure holiday for 4 people is £8015.
Step-by-step explanation:
To calculate the initial payment needed when booking an adventure holiday for 4 people, we need to multiply the cost per person (£2000) by the number of people (4). This will give us the total cost of the holiday. Then, we need to add the administration fee (£15) to the total cost to get the final amount. The equation will be:
Total Cost = (Cost per person) x (Number of people) + (Administration fee)
Total Cost = £2000 x 4 + £15 = £8015.
Therefore, the initial payment needed when booking an adventure holiday for 4 people is £8015.