Throughput accounting

I cam across this question and am struggling to see where the answers came from. Can anyone help explain the steps to getting the below answers?

Firstly the answers:
Assembly hours for maximum production: 143.75
Quality Control hours for Max production: 178.33
Packaging Hours for maximum production: 234.17

Sales price per unit:
Alpha: 2
Beta: 2.25
Gamma: 1.75

Direct Materials cost P.U:
Alpha: .5
Beta: .81
Gamma: .35

Direct Labour cost P.U:
Alpha: .3
Beta: .6
Gamma: .5

Machine time per unit:
(Assembly in minutes)
Alpha: 2
Beta: 3
Gamma: 2.5

(Quality control in minutes)
Alpha: 3
Beta: 4
Gamma: 2

(Packaging in minutes)
Alpha: 4
Beta: 5
Gamma: 3

Weekly Sales demand
Alpha: 1,000 Units
Beta: 1,500 Units
Gamma: 850 Units

Operating expenses, including labor are $4,000
The Maximum hours for the machine are:
150 hours (Assembly)
170 hours (Quality Control)
250 hours (Packaging)

Can you help explain the steps to resolving this as I need these answers to calculate the ratio later on?

Thanks in advance for your help,

Tom