SOLUTION: a scientist needs 30 liters of a 60% solution. He has a 40% solution and a 70% solution. How many of each does he need to get 30 liters of a 60% solution?

Algebra.Com
Question 712266: a scientist needs 30 liters of a 60% solution. He has a 40% solution and a 70% solution. How many of each does he need to get 30 liters of a 60% solution?
Answer by josgarithmetic(39617)   (Show Source): You can put this solution on YOUR website!
ASSIGN VARIABLES TO ALL QUANTITIES
L, the lower concentration of available material 40%
H, the higher concentration of available material 70%
T, the target concentration of resulting mixture 60%
x, the amount of lower concentrated material to use, unknown
y, the amount of higher concentrated materaial to use, unknown
M, amount of the resulting mixture 30 Liters


EQUATIONS



SOLVE SYMBOLICALLY







, and since the two differences here would both be negative,
we can multiply by (-1)/(-1),



After you substitute the values and compute x, use y=M-x to compute the value for y.

, ... and you know what else to do..
RELATED QUESTIONS

A scientist needs 60 liters of a 60% acid solution. He currently has a 40% solution and a (answered by josgarithmetic)
A scientist needs 60 liters of a 40% acid solution. He currently has a 30% solution and a (answered by mananth)
A scientist needs 60 liters of a 60% acid solution. He currently has a 40% solution and a (answered by stanbon)
Help me please! Gabe Amodeo, a nuclear physicist needs 30 liters of a 40% acid... (answered by josmiceli)
Gabe​ Amodeo, a nuclear​ physicist, needs 60liters of a 40% acid solution. He... (answered by jim_thompson5910,greenestamps)
Gabe Amodeo,a nuclear physicist, needs 50 liters of a 60% acid solution. he currently has (answered by ewatrrr)
Gave Amoseo , a nuclear physicist , needs 60 liters of a 40% acid solution . He currently (answered by ikleyn)
Gabe, a Nuclear Physicist, needs 90 liters of a 50% acid solution. He currently has a 30% (answered by josmiceli)
Gabe​ Amodeo, a nuclear​ physicist, needs 60 liters of a 40​% acid... (answered by josgarithmetic)