Question

HELP! Sunflower Seed Mixture Math Problem: Agway Gardens has sunflower seeds that sell for $0.49 per pound?

Agway Gardens has sunflower seeds that sell for $0.49 per pound and gourmet bird seed mix that sells for $0.89 per pound. How much of each must be mixed to get a 20-pound mixture that sells for $0.73 per pound?

I came up with this equation:

let S = Sunflower seeds

B = Bird seed mix

I came up with this equation: (0.49S + 0.89B) / 20 = 0.73

But I couldn't find the solution.

Thank you for your help!

Answer

as you said

s= sunflower seed in pounds

b= bird seed mix in pounds

total weight = 20 lb

then , s= 20-b

(0.49s+0.89b) =20*0.73

0.49(20-b)+0.89b=20*0.73

0.49*20-0.49b+0.89b=20*0.73

9.8+0.4b=14.6

0.4b=14.6-9.8=4.8

b=4.8/0.4=12

so bird seed mix=12 pounds

sun flower seeds=20-12=8 pounds

check

0.49*8+0.89*12=3.92+10.68=14.6

20*0.73=14.6

May 13 at 12:5

You need to be clearer in you definitions. "S" is not just sunflower seeds, it is the number of pounds of sunflower seeds to use

S + B = 20

Now you have two equations in two unknowns, and can solve.

May 13 at 15:51

since there are two unknowns you will need two equations.

since S and B represent the total amount in pounds and you know you need 20 pounds, the 2nd equation would be

S + B = 20

then you can solve both equations noting that S = 20 - B so

(.49*(20-B+.89*B)/20=.73

solve for B then plug that into either of the first equations to solve for A

May 13 at 20:0

If S is the number of pounds of sunflower seeds, 20-S is the number of pounds of bird seed in the mix. Then your equation becomes [0.49S + 0.89(20-S)]/20 = 0.73

Now you can solve for S, and hence for B.

May 14 at 0:32