Answer How many liters of a 20% acid solution should be mixed with 30 liters of 50% acid solution in order to obtain a 40% solution. ... x=15 liters 15*(.20 pure acid)=3 liters 30*(.50 pure acid)=15 liters That is 18 liters pure acid That is 45 liters solution *0.45 pure acid=18 liters.
As more pure acid is added, the concentration of acid approaches 0.
The fifth term of the geometric sequence would be 0.972
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Given Information
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Total number of people = 165
Adult = $6
Child = $2
Total collected = $618
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Assumptions
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Let x be the number of adults and y be the number of children
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Form equations
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Total number of people
x + y = 165
Total amount collected
6x + 2y = 618
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Ans: The two equations are x + y = 165 and 6x + 2y = 618
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The question is not asking for it but if you need to solve the equation to find the answer to x and y
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Present the two equations and solve for x and y
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x + y = 165 ------------------------- (eqn 1)
6x + 2y = 618 ------------------------- (eqn 2)
(eqn 1) :
x + y = 165
x = 165 - y ------------------------- substitute into (eqn 2)
6(165 - y) + 2y = 618
990 - 6y + 2y = 618
4y = 990 - 618
4y = 372
y = 93 ------------------------- substitute into (eqn 1)
x + y = 165
x + 93 = 165
x = 165 - 93
x = 72
x = 72 and y = 93
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Ans: 72 adults and 93 children
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