Question

The perimeters of four triangles are as follows: 3, 9, 27, 81.
What would be the perimeter of a fifth triangle that follows the pattern?
A. 87
B. 100
C. 135
D. 243

Answer 1

The correct answer would be D. 
Explanation: Each time, the number is multiplied by 3 
(3×3=9, 9×3=27, 27×3=81, 81×3=243)
So therefore 243 would be the perimeter of the fifth triangle.