EV Maths Fail

[Sterillium]

I am pathologically stupid when it comes to maths.

A family member is in the process of ordering a new Peugeot E-2008 and they are getting a 7kw wall charger fitted at home.

Because I like cars, they've asked me how to work out what the cost of their daily commute will be, compared to the old diesel car that they have upgraded from... and I haven't got a bloody clue.

Their commute is approximately 20 miles (each way) of suburban/countryside B roads.
Their old car was a Peugeot diesel running at around 50mpg.
They are already with Octopus Energy and will sometimes use the "off-peak" rate and sometimes use the "peak" rate.

Octopus Energy said:

Unit rate (23:30 - 05:30):

10.00p/ kWh
Unit rate (05:30 - 23:30):

42.90p/ kWh
Standing Charge:

51.09p/ day

What they want is:

1. Weekly cost of the old diesel (assuming five days commute per week).
2. Weekly cost of the new EV when charged during "off-peak" rates (assuming five days commute per week).
3. Weekly cost of the new EV when charged during "peak" rates (assuming five days commute per week).

I think the answer to number one is £31.80, but I have no clue about the others!