I can’t remember how to do this if I try a bit longer I can probably figure it out but not sure exactly. Please If anyone can help so I can come back and check it later

Answer:
£2.38
Step-by-step explanation:
2.5 cost £1.40
4.25 cost £ x
so x=(4.25*1.40)/2.5=5.95/2.5=£2.38