Look at the figures. The rectangles represent tables and the dots represent chairs for guests at a conference.
- How many tables will Figure 7 have?
- How many chairs will Figure 5 have?
- If there are 70 guests at the conference, how many tables will be needed?
(a)
Pattern for the number of tables
Figure 1: 1
Figure 2: 2
Figure 3: 3
Formula
Number of tables = Figure number
Number of tables for Figure 7 = 7
(b)
Pattern for the number of chairs
Figure 1: 1 x 4 + 2 = 6
Figure 2: 2 x 4 + 2 = 10
Figure 3: 3 x 4 + 2 = 14
Formula
Number of chairs = Figure number x 4 + 2
Number of chairs for Figure 5
= 5 x 4 + 2
= 22
(c)
70 guests: 70 chairs
Figure number for 70 chairs
= (70 - 2) ÷ 4
= 17
Number of tables for Figure 17 = 17
Answer(s): (a) 4; (b) 22; (c) 17