What is the next number in this pattern 1/10 1/5 3/10 2/5 1/2

Restrictions on f(x) = 1/x+5 and g(x) = x-2

Amerchant has coffee worth $60 a pound that she wishes to mix with 50 pounds of coffee worth $90 a pound to get a mixture that she will sell for $70 a pound. how many pounds of the & 60 coffee should be used?

Iwill make brain if you me correctly fill this out needs due today pls and send it back to me (click the link and you will get it)