Which expression is equivalent to n5 +n5+n+5n+5n?

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?

How do i do this? i don’t understand

Acircle has a circumference of 28.36 units what is the diameter of the circle