The answer must be a whole number because for example how are you suppose to fit half a child on a bus that can hold 44 people when it already holds that amount.
It will always be a whole number because if there are several left over students they will be put in another bus with more empty seats.
-1 is the Y intercept for the graph
6 cakes ... £2.40
10 cakes ... £x = ?
If you would like to know how much do 10 cakes cost, you can calculate this using the following steps:
6 * x = 10 * 2.40
6 * x = 24 /6
x = 24/6
x = £4
Result: 10 cakes cost £4.