How much birdseed?

Question

Birdseed costs $0.54 a pound and sunflower seeds cost $0.84 a pound. Angela​ Leinenbachs' pet store wishes to make a 40​-pound mixture of birdseed and sunflower seeds that sells for $0.62 per a pound. How many pounds of each type of seed should she​ use?

Answer 1

Hello, Elio.

Okay, so let's call the amount of birdseed needed X.

Since the total amount needed is 40 pounds, then the amount of sunflower seeds needed is 40 - X.

Since birdseed is .54/pound, it will cost .54X.

Since the sunflower seeds cost .84/pound, it will be .84(40 - X).

So, now you can add those up and they need to be equal to 40 pounds at .62/pound.

So,

.54X + .84(40 - X) = .62(40)

Now, solve:

.54X + 33.60 - .84X = 24.80

8.80 = .30X

29 1/3 pounds = X

So, she needs 29 1/3 pounds of birdseed and 40 - 29 1/3 = 10 2/3 pounds of sunflower seeds.