Question 15c

Figure 1 → 5 Figure 2 → 5 + 3 = 8 Figure 3 → 8 + 3 = 11 Figure 4 → 11 + 3 = 14 Figure 5 → 14 + 3 = 17

starting number → 5 adding number → 3

311 squares → (total - starting number) ÷ adding number + 1 = (311 - 5) ÷ 3 + 1 = 103