Soru

Zorluk: OrtaFraction Addition and Subtraction in Context

An Equipment Operator is laying a base layer of crushed rock for a new supply road. The project requires a total of 221422 \frac{1}{4} tons of crushed rock. The first dump truck delivers 8128 \frac{1}{2} tons, and the second dump truck delivers 7137 \frac{1}{3} tons. How many more tons of crushed rock are needed to complete the base layer?

  1. 65126 \frac{5}{12}Cevap
  2. B
    617206 \frac{17}{20}
  3. C
    77127 \frac{7}{12}
  4. D
    3811238 \frac{1}{12}

Cevap

65126 \frac{5}{12} tons
To find the remaining amount needed, first calculate the total crushed rock delivered by adding the two truckloads. Convert the fractions to a common denominator of 66: 812=8368 \frac{1}{2} = 8 \frac{3}{6} and 713=7267 \frac{1}{3} = 7 \frac{2}{6}. Adding these gives 155615 \frac{5}{6} tons delivered. Next, subtract this amount from the total required, 221422 \frac{1}{4}. Convert to a common denominator of 1212: 2214=2231222 \frac{1}{4} = 22 \frac{3}{12} and 1556=15101215 \frac{5}{6} = 15 \frac{10}{12}. Since 312\frac{3}{12} is less than 1012\frac{10}{12}, borrow 11 (or 1212\frac{12}{12}) from 2222 to get 21151221 \frac{15}{12}. Finally, subtract: 211512−151012=651221 \frac{15}{12} - 15 \frac{10}{12} = 6 \frac{5}{12} tons.

Adım Adım Çözüm

1
Calculate the total amount of crushed rock delivered.
812+713=836+726=15568 \frac{1}{2} + 7 \frac{1}{3} = 8 \frac{3}{6} + 7 \frac{2}{6} = 15 \frac{5}{6}
The total delivered is the sum of the two truckloads, requiring a common denominator of 6.
2
Set up the subtraction from the total required amount using a common denominator.
2214−1556=22312−15101222 \frac{1}{4} - 15 \frac{5}{6} = 22 \frac{3}{12} - 15 \frac{10}{12}
To find the remaining amount, subtract the delivered total from the required total using the least common multiple of 4 and 6, which is 12.
3
Regroup (borrow) to perform the subtraction.
211512−151012=651221 \frac{15}{12} - 15 \frac{10}{12} = 6 \frac{5}{12}
Since 3/12 is smaller than 10/12, borrow 1 (as 12/12) from the whole number 22 to make it 21 15/12, then subtract the whole numbers and numerators.

Anahtar Kavram

Adding and subtracting mixed numbers with unlike denominators, including regrouping.
Bu soruyu puanla