I can do the first 2 parts of this question (which I have included in case they add anything to part 3), but cannot work out the final part. Can any one put me out of my misery?
The total cost of one ticket from G to J and one ticket from G to I is £1
The total cost of one ticket from G to J and one ticket from H to J is £1.20
The total cost of one ticket from G to J, one ticket from G to H, and one ticket
from I to J, is £1.30.
What is the cost of one ticket from G to J?
A B C D E F G H I J [Bus stops arranged on a circle in the question)
I think if you make each little bit of the journey represented by a letter so GH=a HI=b IJ=c
so G to J = a+b+c
2a+b+2c = £1.30
add the lot together : 5a+5b+5c = £3.50 so one trip a+b+c (or GtoJ)= 70p