SOLUTION: The ratio of the # of Conor's marbles to the # of Lillian's marbles is 3:4. After Conor bought another 60 marbles, he had twice as many marbles as Lillian. How many marbles did C

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Question 156257: The ratio of the # of Conor's marbles to the # of Lillian's marbles is 3:4. After Conor bought another 60 marbles, he had twice as many marbles as Lillian. How many marbles did Conor have at first?
I don't know how to start to figure this out. Do I use x represent Conor's marbles or Lillian's marbles?
Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website!
The ratio of the # of Conor's marbles to the # of Lillian's marbles is 3:4. After Conor bought another 60 marbles, he had twice as many marbles as Lillian. How many marbles did Conor have at first?
:
Let x = no. marbles Conor had originally
Let y = no. marbles Lillian has
:
Write an equation for the statement:
"The ratio of the # of Conor's marbles to the # of Lillian's marbles is 3:4."
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Cross multiply and we have:
4x = 3y
:
"After Conor bought another 60 marbles, he had twice as many marbles as Lillian."
x + 60 = 2y
x = (2y-60)
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Substitute (2y-60) for x in the 1st equation
4(2y-60) = 3y
8y - 240 = 3y
8y - 3y = 240
5y = 240
y =
y = 48 marbles for Lillian
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Find x
x = 2y - 60
x = 2(48) - 60
x = 96 - 60
x = 36 marbles for Conor originally
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Check solution
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