Soru

Zorluk: ZorFractions, Decimals, Percentages, and Approximations

Simplify the expression 31311423 of 212+116\frac{3\frac{1}{3} - 1\frac{1}{4}}{\frac{2}{3} \text{ of } 2\frac{1}{2} + 1\frac{1}{6}} and express the answer correct to three significant figures. What is the resulting value?

  1. 0.7350.735Cevap
  2. B
    0.8520.852
  3. C
    1.071.07
  4. D
    0.7360.736

Cevap

The simplified value correct to three significant figures is 0.7350.735.
Simplifying the numerator yields 2512\frac{25}{12}. For the denominator, applying BODMAS gives 23×52=53\frac{2}{3} \times \frac{5}{2} = \frac{5}{3}, and adding 76\frac{7}{6} results in 176\frac{17}{6}. Dividing the numerator by the denominator gives 2534=0.73529...\frac{25}{34} = 0.73529.... Rounding to three significant figures gives 0.7350.735.

Adım Adım Çözüm

1
Convert mixed fractions to improper fractions and simplify the numerator.
313114=10354=401512=25123\frac{1}{3} - 1\frac{1}{4} = \frac{10}{3} - \frac{5}{4} = \frac{40 - 15}{12} = \frac{25}{12}
Find a common denominator (1212) to subtract the fractions.
2
Evaluate the denominator following BODMAS rules (performing 'of' before addition).
23 of 212=23×52=53\frac{2}{3} \text{ of } 2\frac{1}{2} = \frac{2}{3} \times \frac{5}{2} = \frac{5}{3}. Then add 1161\frac{1}{6}: 53+76=10+76=176\frac{5}{3} + \frac{7}{6} = \frac{10 + 7}{6} = \frac{17}{6}.
'of' signifies multiplication and takes precedence over addition.
3
Divide the numerator by the denominator.
2512176=2512×617=252×17=2534\frac{\frac{25}{12}}{\frac{17}{6}} = \frac{25}{12} \times \frac{6}{17} = \frac{25}{2 \times 17} = \frac{25}{34}
Dividing by a fraction is equivalent to multiplying by its reciprocal.
4
Convert the resulting fraction to a decimal and round to three significant figures.
2534=0.735294...0.735\frac{25}{34} = 0.735294... \approx 0.735
The first non-zero digit is 77. The first three significant figures are 7,3,57, 3, 5, followed by 22, so we round down.

Anahtar Kavram

Compound Fraction Operations and Approximation
Bu soruyu puanla