Question

Difficulty: MediumFraction Operations

A tailor has a bolt of fabric that is 201420\frac{1}{4} yards long. He cuts 5345\frac{3}{4} yards of fabric to make a suit jacket and another 3583\frac{5}{8} yards to make a pair of trousers. How many yards of fabric are remaining on the bolt?

  1. 107810\frac{7}{8}Answer
  2. B
    1171211\frac{7}{12}
  3. C
    181818\frac{1}{8}
  4. D
    111811\frac{1}{8}

Answer

107810\frac{7}{8}
The correct answer is found by first calculating the total fabric used (534+358=9385\frac{3}{4} + 3\frac{5}{8} = 9\frac{3}{8} yards). Subtracting this from the original 201420\frac{1}{4} yards requires converting to a common denominator (2028−93820\frac{2}{8} - 9\frac{3}{8}) and then borrowing from the whole number (19108−93819\frac{10}{8} - 9\frac{3}{8}) to get exactly 107810\frac{7}{8} yards.

Step-by-Step Solution

1
Find the total amount of fabric used by adding 5345\frac{3}{4} and 3583\frac{5}{8}.
534+358=568+358=8118=9385\frac{3}{4} + 3\frac{5}{8} = 5\frac{6}{8} + 3\frac{5}{8} = 8\frac{11}{8} = 9\frac{3}{8} yards.
Before finding the remaining amount, the total amount removed from the bolt must be calculated by finding a common denominator.
2
Subtract the total used fabric from the original length of the bolt.
2014−938=2028−93820\frac{1}{4} - 9\frac{3}{8} = 20\frac{2}{8} - 9\frac{3}{8}.
Subtracting the used amount from the initial amount determines how much fabric is left.
3
Borrow from the whole number to complete the subtraction.
19108−938=107819\frac{10}{8} - 9\frac{3}{8} = 10\frac{7}{8} yards.
Since 22 is less than 33 in the numerators, 11 whole (8/88/8) must be borrowed from 2020 to make the subtraction possible.

Key Concept

Adding and subtracting mixed numbers with unlike denominators, including borrowing.
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