The ratio is 5:7. This means that there are 12 parts (5+7) that will be distributed between Alex and Ben.
Let's figure out how much 1 part is by dividing £240 by the 12 parts we need.
£240/12 = £20
Out of the 12 parts, Ben gets 7 parts.
Therefore, Ben's share must be 7 × £20 = £140
