Your method is completely correct. The first term will be 6 and each subsequent term can be obtained by adding 6 to the previous one, meaning the common difference is 6. The number of terms is given by the highest number that is divisible by 6 and dividing it by 6; that is 996/6 = 166
Then we simply apply the formula for arithmetic sequence sum:
S = n/2 [2a₁ + (n - 1)d]
S = 166/2 [ 2(6) + (166 - 1)6]
S = 83,166
First Chart: Perimeter
Square Portion:
Original Side Lengths: P = 4 (1 + 1 + 1 + 1 ) =4
Double Side Lengths: P = 8 (2 x 4 = 8)
Triple Side Lengths: P = 12 (4 x 3 = 12)
Quadruple Side Lengths: P = 16 (4 x 4 = 16)
Rectangle Portion:
Original Side Lengths: P = 6 (1 x 2 + 2 x 2 = 6)
Double Side Lengths: P = 12 (2 x 2 + 4 x 2 = 12)
Triple Side Lengths: P = 24 (4 x 2 + 8 x 2 = 24)
Quadruple Side Lengths: P = 48 (8 x 2 + 16 x 2 = 48)
Second Chart: Area
Square Portion:
Original Side Lengths: A = 1 (1 x 1 = 1)
Double Side Lengths: A = 4 (2 x 2 = 4)
Triple Side Lengths: A = 9 (3 x 3 = 9
Quadruple Side Lengths: A = 16 ( 4 x 4 = 16)
Rectangle Portion:
Original Side Lengths: A = 2 ( 1 x 2 = 2 )
Double Side Lengths: A = 8 ( 2 x 4 = 8)
Triple Side Lengths: A = 18 ( 3 x 6 = 18)
Quadruple Side Lengths: A = 32 (4 x 8 = 32)
Answer:
option C is the correct answer