Please answer ASAP and if you do you will get Brainliest. Catherine buys a gallon of ice cream from the store. After taking it home, she eats a fifth of a gallon of ice cream. Her sister eats some of the ice cream as well. If two-thirds of the original amount of ice cream is left, then what fraction of a gallon of ice cream did her sister eat?

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Answer:

Catherine's sister ate 2/15 gallons of the ice cream.

[tex]\displaystyle \frac{2}{15}[/tex].

Step-by-step explanation:

Let [tex]x[/tex] be the amount of ice cream that Catherine's sister ate, in gallons.

  • Original amount: 1 gallon.
  • What Catherine ate: [tex]\displaystyle \frac{1}{5}[/tex] gallons.
  • What Catherine's sister ate is assumed to be [tex]x[/tex] gallons.
  • What's left: [tex]\displaystyle \frac{2}{3}[/tex] gallons.

Consider the relationship:

[tex]\text{Original amount - What Catherine ate - What Catherine's Sister ate}\\ =\text{ What's left.}[/tex].

That is:

[tex]\displaystyle 1- \frac{1}{5} - x = \frac{2}{3}[/tex].

Add [tex]x[/tex] to both sides of this equation:

[tex]\displaystyle 1 - \frac{1}{5} = \frac{2}{3} +x[/tex]

Substract [tex]\displaystyle \frac{2}{3}[/tex] from both sides:

[tex]\displaystyle 1 - \frac{1}{5} - \frac{2}{3} = x[/tex].

Convert the denominator of all three numbers on the left-hand side to [tex]3 \times 5 = 15[/tex]

[tex]\displaystyle \frac{15}{15} - \frac{3}{15} - \frac{10}{15} = x[/tex].

[tex]\displaystyle x = \frac{2}{15}[/tex].

In other words, Catherine's sister ate [tex]\displaystyle \frac{2}{15}[/tex] gallons of the ice cream.

To solve this, we need to add the 1/5 of the ice cream to the 2/3 left of ice cream to find out how much her sister ate.

First, we need a common denominator. We can multiply 3 by 5 to get a common denominator easiest, since they are both multiples of it.

3*5=15

Now multiply the numerators by the amount the denominators were multiplied by.

1*3=3 so 3/15

2*5=10 so 10/15

Now, add them together.

10/15+3/15= 13/15.

Finally, subtract that amount from the original full amount of ice cream (15/15) to get the amount her sister ate, since that is the only unknown value left.

15/15-13/15=2/15.

Because 15 isn’t divisible by 2, we can’t simplify this fraction anymore.

Her sister ate 2/15 of a gallon of ice cream.

Hope this helps!

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