Accounting for labour

Hello Sir

I am having problems with accounting to the labour

Firstly-
When the say 601 units-650 units – is it actually 49 units or 50 units ( a very sill question but just wanted to be sure)

Secondly- I am super confused with overtime payment and overtime preimium and when is what a direct labour cost . In some questions they say that the overtime payments for direct labour is a direct cost

Thirdly- What is this time and quarter and how do we calculate the direct wages with that

Lastly – There is this question in BPP which I cannot understand
Jaffa Co employs two types of labour: skilled workers(direct labour) and semi skilled workers(indirect labour). Skilled labours are paid $ 10 per hour and semi skilled are paid $ 5 per hour.

Skilled labour works 20 hours overtime, 12 on specific order and 8 on general
Overtme is paid at time and quarter.

Semi skilled worked 30 hours overtime, 20 for specific and rest is geneta. Overtime is paid at time quarter

ANSWER- SIr, while calculating the skilled labour they do

Speicifc overtime = 12x10x1.25=150

What I do not understand is the division of general overtime as they do it like this

General ( 8x10x1) = 80 ( treated as direct, WHYYY)
General (8x10x0.25)=20 ( treated as indirect, WHY)

I cant undertand how they divided the 1.25 and how they get it

and why is sone as general

THANKS A LOT