Nomkhosi is a teacher in Smithfield and lives in Rouxville. She travels 39,2 km at an average speed of 80 km/h daily to work. It normally takes her approximately 29 minutes. Due to the road maintenance, she must add an extra 10 min for one stop and go on the road.

Nomkhosi travels 39.2 km to work and 39.2 km back home.

Assuming a 5-day work week:

The total number of kilometers that she travels per week is $\boxed{\text{392 km}}$.

3.1.2

Normal travel time = 29 minutes.
Extra time due to road maintenance = 10 minutes.

Since 1 hour = 60 minutes:

It takes Nomkhosi $\boxed{\text{0.65 hours}}$ to get to work due to Stop and go.

3.1.3

School starts at 07:30. Nomkhosi must be at school 10 minutes before school starts.

From 3.1.2, the total travel time to work (one way) is 39 minutes.

To subtract 39 minutes from 07:20:
07:20 is 7 hours and 20 minutes.
Subtract 20 minutes: 07:00. Remaining to subtract: $39 - 20 = 19$ minutes.
Subtract 19 minutes from 07:00: 06:41.
Nomkhosi must leave her home by $\boxed{\text{06:41}}$.

3.2.1

2 litres of Oros concentrate makes 8 litres of juice.

Since 1 litre = 1000 milliliters:

Given: 1 cup = 250 ml.

$\boxed{\text{32 cups}}$ can be served from a 2-litre concentrate juice.

3.2.2

Mrs. Marais sold 58 packets, and each packet had 5 scones.

The recipe uses 200 grams of self-raising white flour and "Serves 9 people". Assuming one serving is one scone, then one batch makes 9 scones.

Since 1 kg = 1000 grams:

Rounding to two decimal places:

Approximately $\boxed{\text{6.44 kg}}$ of self-raising white flour was used.

3.2.3

The recipe uses 50 grams of butter.

Since 1 kg = 1000 grams:

The amount of butter is $\boxed{\text{0.05 kg}}$.

3.2.4

Butter = 50 grams
Self-raising white flour = 200 grams

Divide both sides by the greatest common divisor, which is 50.

The ratio of butter to self-raising flour in simplified form is $\boxed{1:4}$.