Hello, I need help for my 5th grader...Solve the problem by working backward. Write the ans. in a compl. sentence. Mara followed a recipe she found on the net to make her own perfume. She started by adding jojoba oil to a small bottle. Then she added 2 1/3ozs of sandalwood oil, 1 1/4ozs of musk oil, and 1 5/12ozs of frankincense oil. Mara made a total of 8ozs of perfume. How much jojoba oil did she use?
First, let's find the common denominators and add the fractions.
2 1/3 = 2 4/12
1 1/4 = 1 3/12
1 5/12 = 1 5/12
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. . . . 4 12/12 = 5
Subtract 5 from 8 to find the amount of jojoba oil Mara used.
In your opinion , when would it be advantageous to record a fractional answer in each of following forms? a mixed number, an improper number, a decimal.
To solve this problem by working backward, we need to find the amount of jojoba oil Mara used by subtracting the amounts of the other three oils from the total volume of the perfume.
First, we add up the amounts of sandalwood oil, musk oil, and frankincense oil:
2 1/3 + 1 1/4 + 1 5/12 = (7/3) + (5/4) + (17/12)
To add fractions with different denominators, we need to find a common denominator. In this case, the smallest common multiple of 3, 4, and 12 is 12. So, we convert each fraction to twelfths:
(7/3) = (7/3) x (4/4) = 28/12
(5/4) = (5/4) x (3/3) = 15/12
(17/12) = 17/12
Now, let's add the fractions:
28/12 + 15/12 + 17/12 = 60/12
Next, we simplify the fraction:
60/12 = 5
So, the combined amount of the sandalwood oil, musk oil, and frankincense oil is 5 ounces.
To find the amount of jojoba oil Mara used, we subtract the combined amount of the other oils from the total volume of the perfume:
8 - 5 = 3
Therefore, Mara used 3 ounces of jojoba oil to make her perfume.
In summary, Mara used 3 ounces of jojoba oil to make her own perfume.