Question

See the following pattern carefully:

1. If n denotes the number of figures and S denotes the number of matches; find S in terms of n.
2. Find how many matches are required to make the :
   (1) 15th figure
   (2) 40th figure
3. Write a discretion of the pattern in words.

Answer 1

1. n	1	2	3	4
   S	7	10	13	16

   
   S = 3n + 4
2.  (1) 15th figure has = 3 x 15 + 4 = 49 matches
   (2) 40th figure has = 3 x 40 + 4 = 124 matches
3. It can easily be observed that each time the figure (n) is increased by 4, the number of matches (S) increased by 3.