4. A company, which is making 140 bicycles each week, plans to increase its production. The number of bicycles produced is to be increased by \(d\) each week, starting from 140 in week 1 , to \(140 + d\) in week 2 , to \(140 + 2 d\) in week 3 and so on, until the company is producing 206 in week 12.
- Find the value of \(d\).
After week 12 the company plans to continue making 206 bicycles each week.
- Find the total number of bicycles that would be made in the first 52 weeks starting from and including week 1.