Study the series of figures carefully.
- Complete the table.
- Find the number of sticks needed in Pattern Number 30.
- Find the number of dots needed when 511 sticks are used.
Pattern Number |
Number of sticks |
Number of dots |
1 |
3 |
3 |
2 |
8 |
5 |
3 |
13 |
7 |
... |
... |
... |
15 |
? |
31 |
16 |
63 |
? |
(a)
Pattern for the number of sticks
Pattern 1: 1 x 4 - 1 = 3 sticks
Pattern 2: 2 x 4 - 1 = 7 sticks
Pattern 3: 3 x 4 - 1 = 11 sticks
Formula:
Number of sticks needed = Pattern number x 4 - 1
Number of sticks needed for Pattern 15
= 15 x 4 - 1
= 59
Pattern for the number of dots
Pattern 1: 1 x 2 + 1 = 3 dots
Pattern 2: 2 x 2 + 1 = 5 dots
Pattern 3: 3 x 2 + 1 = 7 dots
Formula:
Number of dots = (Pattern Number x 2) + 1
Number of dots needed for Pattern 16
= 16 x 2 + 1
= 33
(b)
Number of sticks needed in Pattern 30
= 30 x 4 - 1
= 119
(c)
Pattern Number x 4 - 1 = 511
Pattern Number x 4 = 511 + 1 = 512
Pattern number = 512 ÷ 4 = 128
Number of dots needed in Pattern 128
= 128 x 2 + 1
= 257
Answer(s): (a) 33, 59; (b) 119; (c) 257