What is 63.5 divided by 5 estimating qoutients i need

What is the approximate circumference of the circle shown below?

Two blends of tea are mixed to make a blend that will be sold at the fair. black tea sells for $2.20 per pound and orange pekoe tea sells for $3.00 per pound. how much of each should be used to obtain a 4lb blend selling for $2.50 per pound?

Which describes the difference between the graph of f(x)=x^2 and g(x)=-(x^2-2)