Jemima has to post 2 books to her sister. She weighs them on the kitchen scales, which gives readings correct to the nearest 5g.
"Algebra made Easy” is weighed at 450g.
“ Terrible Trigonometry” is weighed at 95g.
She packs them using wrapping that is weighed at 120g.
The post office charges 79p for the first 510g of any parcel, and then 11p for
each extra 40g.
Find the maximum that Jemima might have to pay to post the parcel.