Find an equation that explains the problem. We can see how many goals the players have scored in comparison to each other. The person with the fewest goals is Chris. Let us say he score x goals. Then we can see that Kieran has scored 8 more than Chris, ie x + 8. Jermaine scored 5 more goals than Kieran, therefore x + 8 + 5 = x + 13. Now we have the amount of goals each person scored relative to each other. The total number of goals scored was 72, thus all of these amounts must equal 72.
x + (x + 8) + (x + 13) = 72
Now we can rearrange and solve for x.
3x + 21 = 72
3x = 51
x = 17
Remember, the question is asking the number of goals Jermaine scored. He scored x + 13 goals. There Jermaine scored 17 + 13 = 30 goals. To check our answer lets make sure the numbers add up. Kieran scored x + 8 goals : 17 + 8 = 25. 17 + 25 + 30 = 72.