Let x be the number of pounds of the $1.35 beans. The cost of those beans is $1.35 * x, or 1.35x.
<span>Let y be the number of pounds of the $1.05 beans. The cost of those beans is $1.05 * y, or 1.05y. </span>
<span>We know that 120 pounds of the mix sells for $1.15/pound, for a total of 120 * 1.15 = $138. </span>
<span>x + y = 120 </span>
<span>1.35(x) + (1.05)y = 138 </span>
<span>We can rewrite the first as </span>
<span>x = -y + 120 </span>
<span>Now we can substitute (-y + 120) in for (x) in the second equation, because we just proved they're equal. </span>
<span>1.35(x) + 1.05(y) = 138 </span>
<span>1.35(-y + 120) + 1.05y = 138 </span>
<span>-1.35y + 162 + 1.05y = 138 </span>
<span>-0.3y + 162 = 138 </span>
<span>-0.3y = -24 </span>
<span>y = 80 </span>
<span>And since x + y = 120, that means x = 40. </span>
<span>Check: </span>
<span>40 pounds of x at $1.35 costs 40 * 1.35, or $54. </span>
<span>80 pounds of y at $1.05 costs 80 * 1.05, or $84. </span>
<span>Do those add up to our target total, according to the question, of 120 * 1.15 = $138? </span>
2p-b=c-ap
2p+ap=c+b
p(2+a)=c+b
So, p=(c+b)/(2+a)
According to google A. Would be 2.375 or as a fraction it would be 2 3/8
Qty · % = Total
Drink 1: x .25 = .25x
Drink 2: 15 - x .10 = .10(15 - x)
Mixture: 15 .21 = .25x + .10(15 - x)
(15)(.21) = .25x + 1.5 - .10x
3.15 = .15x + 1.5
1.65 = .15x
11 = x
Drink 1 (25%) is 11 liters
Drink 2 (10%) is 15 - 11 = 4 liters
