What is the series you are referring too?
First you do 7.9/ 1/4, that gets you 1.975. that is how much blue paint there is. Then you do 7.9-1.975= 5.925, which is how much white paint she used. So in total she used 1.975 pints of blue paint, and 5.925 pints of white paint.
The way the question is worded is a little confusing.
I think I would say 10m. It could be 5m, but usually they list length first, then width. The perimeter, the whole distance around the outside, is 30 m (10 + 10 + 5 +5)
