Daphne has been doing jobs for her parents on weekends and they have been paying her for what she does. she chose which jobs to undertake from the list below.

job time taken to complete job payment
washing car 1 hour 30 minutes $6
scrubbing kitchen floor 2 hours $8
supermarket shopping 3 hours $12
laundry 5 hours $21
vacuum cleaning 7 hours $30
and tidying

daphne has been choosing which jobs to do purely on the basis of earning the most money possible. she must choose compete jobs – she cannot do part of one.
in the interest of her education her parents will not allow her to
work for more than eight hours any weekend.

this weekend another job is added to the list above – making breakfast for parents, taking one hour with a $4 payment.

how much more will daphne earn this weekend compared to last weekend?