Answer and Explanation:
Since each row must have the same number of chairs. Therefore, C × R = 36..... 1 Since each row must contain at least 3 chairs and there must be at least 3 rows. Therefore, C and R both are greater than or equal to 3. Thus, the possible arrangements are 3 × 12, 4 × 9, 6 × 6, 9 × 4, 12 × 3. Hence, there are 5 different arrangements are possible.