Step-by-Step Solution
Key Concept: AP equations: $a + 3d = 270$ and $a + 9d = 510 \Rightarrow d = 40, a = 150$.
$a + 3d = 270$ and $a + 9d = 510 \Rightarrow d = 40, a = 150$.
1. Production in 1st year $a = 150$. [1.0 Mark]
2. Production in 8th year $a_8 = 150 + 7(40) = 430$. [1.0 Mark]
[Part 3 Main] $S_6 = \dfrac{6}{2}[2(150) + 5(40)] = 3(300 + 200) = 1500$. [2.0 Marks]
-------------------------------
[Part 3 OR Choice]
$a_2 = 150 + 40 = 190$. Ratio $a_2 : a_8 = 190 : 430 = 19 : 43$. [2.0 Marks]
Correct Answer: 1. 150 bicycles, 2. 430 bicycles, 3. 1500 bicycles (OR Ratio 19 : 43)