To calculate the initial deposit of 20% you’ll need to do 7460*0.20 which is 1492.
The for the total of the 36 months you’ll do 191.60*36 which is 6897.60.
Then to get the total amount Mr. Roberts paid you’ll add the two totals we have 6897.60+1492 which would give the total amount paid of £8389.60.