Some circles were used to create the figures .
- How many circles were used to create Figure 7?
- A pattern is formed with 753 circles. Which figure would it be?
(a)
Pattern for the number of circles
Figure 1: (1 - 1) x 4 + 1 = 1
Figure 2: (2 - 1) x 4 + 1 = 5
Figure 3: (3 - 1) x 4 + 1 = 9
Formula
Number of circles = (Figure number - 1) x 4 + 1
Number of circles for Figure 7
= (7 - 1) x 4 + 1
= 25
(b)
Figure number with 753 circles
= (753 - 1) ÷ 4 + 1
= 752 ÷ 4 + 1
= 189
Answer(s): (a) 25; (b) 189
