John asks…can somebody help me with this math problem?a pharmacist needs 70 liters of a 50% alcohol solution. she has available a 30% solution and 80% solution. how many liters of each solution should she mix to obtain what she needs?Nancy answers:Let x be the volume of 30% solution and y be the volume of 80% solution.
1) x + y = 70 or x = 70 - y
2) 0.3x + 0.8y = 0.5(70)
substitute eq(1) into eq(2):
0.3(70 - y) + 0.8y = 35
21 - 0.3y + 0.8y = 35
0.5y = 14
y = 14/0.5 = 28 liters
using eq(1):
x
