Ron ate pizza with his friends the other day. If they ordered a 12-slice pizza and each of them ate 4 slices, how many friends were there with Ron? Think carefully first, then make a decision:
Let the number of friends that ate with Ron be represented by F. That means the total amount of people that ate that day were 1 + F. If each of them ate 4 slices, and the pizza only has 12 slices, that means there could only have been 12 / 4 = 3 people eating. If the total number of people eating was 3, and if was also represented by 1 + F then we have 3 = 1 + F. Solving for F we have 3 - 1 = F. F = 2 friends ate with Ron. So, the answer is 2.