Q:

Assignment: Mixture Problems InvestigationArnold and Jeremy used two pre-packaged mixes to make lemonade for field day. One of the mixtures contained 20% pure lemon juice and the other contained 70% pure lemon juice. They had hoped to have a final mixture of 20 gallons of 40% pure lemon juice, but when they tasted it, they realized the lemonade was much too tart. Take a look at their calculations and see if you can help them adjust their recipe to get the desired result. Be sure to include at least two vocabulary words used so far in the module in your explanations.1. The boys mixed 10 gallons of the 20% pure lemon juice mix and 10 gallons of the 70% pure lemon juice mix, because they wanted 20 gallons of lemonade at a 40% lemon juice mixture. They thought that because 40% was almost halfway between 20% and 70%, they should just mix equal parts of both, but the lemonade turned out too tart. How much of each should they have used to get a final mixture of 20 gallons at 40% lemon juice? Write your answer in complete sentences. Show all work.The boys should use 140% of pure lemon juice mi to get a final mixture of 20 gallons at 40% lemon juice:if 20:70 the 40:70 - it is more like ration and proportion. 2. Why didn’t Arnold and Jeremy’s plan work?3. What if the desired final mixture was changed to yield a 35% mixture containing pure lemon juice? a. How many gallons of a 20% solution should be mixed with 15 gallons of a 70% solution to yield a final mixture of lemonade containing 35% of pure lemon juice? Write your answer in complete sentences. Show all work.b. How many gallons of lemonade would this combination yield? Write your answer in complete sentences. Show all work.you will be reported for dumb answers

Accepted Solution

A:
1)

By multiplying the number of gallons by percentage you get how much pure lemon juice is in the mixture.
20 * 40% = 8 gallons
10*70%  + 10*20%  = 7 + 2 = 9 gallons
So they wanted a mixture of 8 but ended up getting 9, this is why it was too tart.

To get the correct ratio, let x be number of gallons of 70% and 20-x be number of gallons of 20%. Write an equation equating the gal of lemon juice. Solve for x.

x*70%  + (20-x)*20% = 20*40%
0.7x + 4 -0.2x = 8
0.5x = 4
x = 8
The correct quantities are 8 gal of 70% and 12 gal of 20%.

2)   Their plan did not work because 40 is not exactly halfway between 20 and 70. However, 45 is halfway, so if they wanted a 45% mixture then using equal parts would have worked.

3)
Write another equation equating gal of lemon juice but use 35% for the total instead. Also we are given that 15 of the 70% is used.

15*70%  + x*20% = (15+x)*35%
10.5 + 0.2x = 5.25 + .35x
5.25 = .15x
35 = x

You should use 35 gallons of 20% to make the desired total mixture of 35% lemon juice.
The total number of gallons is 15+x = 15+35 = 50