Chapter 2 - Essential GMAT Quant Skills Flashcards
What is the difference between a proper fraction and an improper fraction?
In a proper fraction, the numerator is smaller than the denominator, while in an improper fraction, the numerator is larger than the denominator.
How is a mixed number A b/c expressed as an improper fraction?
(c • A + b)/c
What is the Least Common Denominator of a fraction?
The smallest nonzero whole number that is divisible by each of the denominators.
How can you tell if two fractions are equivalent?
Two fractions a/b and c/d are equivalent if a x d = b x c
What is the distributive property of division over addition?
a/b + c/b = (a + c)/b
What is the distributive property of division over subtraction?
a/b - c/b = (a - c)/b
How do you add or subtract fractions with unlike denominators?
If fractions don’t have the same denominator, we must first express the fractions with a common denominator before adding or subtracting
How do you multiply fractions?
To multiply fractions, multiply the numerators, then multiply the denominators, then place the product of the numerators over the product of the denominators, and then finally simplify the fraction. In general, (a/b) x (c/d) = ac/bd.
How do you divide fractions?
To divide fractions, change the division sign to a multiplication sign, invert the fraction to the right of the multiplication sign, and then multiply the fractions. In general, (a/b) ÷ (c/d) = (a/b) x (d/c) = ad/bc.
How do you multiply a whole number by a fraction?
When we multiply a whole number and a fraction, we multiply the whole by the numerator, and write this product over the denominator. In general, A x b/c = (A x b)/c
How do you find the reciprocal of a nonzero number?
To get the reciprocal of a non-zero number, divide 1 by that number. Another way to say this is to “take 1 over that number,” or to “take the multiplicative inverse of that number.”
What is the only number that doesn’t have a reciprocal?
Zero
What is a complex fraction?
Complex fractions are fractions whose numerator or denominator or both are also fractions.
What are three methods for simplifying complex fractions?
1) Multiply both the numerator and the denominator by the LCD
2) Write The Numerator and Denominator as a Single Fraction and then Divide
3) The Product of the Means Is The Denominator, and the Product of the Extremes is the Numerator
If a, b, c and d are nonzero, (a/b)/(c/d) = ad/bc
What is the bowtie method?
If we have two positive fractions, A and B, and if the product of Denominator B and Numerator A is greater than the product of Denominator A and Numerator B, then A is greater than B. In general, given two positive fractions a/b and c/d, a/b > c/d if ad > bc.