How many days would it take for the number of magic coin to exceed 50,000

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?

Aflute is on sale for 20% off. including the discount and 8% tax, the sales price is $216.

If you answer right ill give brainliest, : )