Answer:
Step-by-step explanation:
Let L = Lucy, C = Carol and A = Arita , x = Total amount of marbles
Lucy shares 1/3 with Carol and keeps 1/4 for herself.
This means that Carol has 1/3 of the total amount of marbles, Lucy has 1/4 of the total amount of marbles.
C = 1/3x
L = 1/4x
We are also told that Carol has 7 more marbles than Lucy
C = L + 7
Since C = 1/3x and L = 1/4x you can sub these into the above equation and you get:
1/3x = 1/4x + 7
Subtract 1/4x from both sides
1/3x - 1/4x = 7
1/12x = 7
Multiply both sides by 12 to find x.
x = 7 times 12 = 84 (Total amount of marbles = 84)
Amrita gets the remaining number of marbles.
A = x - C - L
A = 84 - 1/3 (84) - 1/4 (84)
A = 35
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