SSAT Upper Level Math : Fractions

Study concepts, example questions & explanations for SSAT Upper Level Math

varsity tutors app store varsity tutors android store

Example Questions

Example Question #281 : Rational Numbers

Convert to a fraction. 

\(\displaystyle 3*10^{-4}\)

Possible Answers:

\(\displaystyle \frac{3}{100000}\)

\(\displaystyle \frac{3}{10000}\)

\(\displaystyle \frac{3}{10000000}\)

\(\displaystyle \frac{3}{1000}\)

\(\displaystyle \frac{3}{100}\)

Correct answer:

\(\displaystyle \frac{3}{10000}\)

Explanation:

First, lets convert the exponent into a fraction. Any negative exponent means it's the reciprocal of the positive exponent. So \(\displaystyle 10^{-4}\) means \(\displaystyle \frac{1}{10^{4}}\). Now lets multiply it with the \(\displaystyle 3\). This means \(\displaystyle 3*\frac{1}{10^4}\) or \(\displaystyle 3*\frac{1}{10000}\) or \(\displaystyle \frac{3}{10000}\).

Example Question #12 : How To Find Decimal Fractions

Convert \(\displaystyle 0.33333333333....\) into a fraction. 

Possible Answers:

\(\displaystyle \frac{33333}{100000}\)

\(\displaystyle \frac{33333333333333}{100000000000000}\)

\(\displaystyle \frac{333}{1000}\)

\(\displaystyle \frac{33}{100}\)

\(\displaystyle \frac{1}{3}\)

Correct answer:

\(\displaystyle \frac{1}{3}\)

Explanation:

Let \(\displaystyle 0.33333333333....\) be \(\displaystyle x\). \(\displaystyle (0.33333333333=x)\) 

Lets multiply \(\displaystyle x\) by \(\displaystyle 10\). Now we have:

\(\displaystyle 3.33333333333= 10x\) 

Lets subtract this equation with the first one and we get:

\(\displaystyle 9x=3\) We do this because we want to get rid of the repeating decimals and now we have a simple equation, isolate \(\displaystyle x\) and we arrive at the final answer. 

Example Question #282 : Rational Numbers

Convert \(\displaystyle 0.857857857857...\) into a fraction.

Possible Answers:

\(\displaystyle \frac{857}{998}\)

\(\displaystyle \frac{857}{1000}\)

\(\displaystyle \frac{7}{9}\)

\(\displaystyle \frac{8}{9}\)

\(\displaystyle \frac{857}{999}\)

Correct answer:

\(\displaystyle \frac{857}{999}\)

Explanation:

Let \(\displaystyle 0.857857857...\) be \(\displaystyle x\)\(\displaystyle (0.857857857...=x)\) 

Lets multiply \(\displaystyle x\) by \(\displaystyle 1000\). I chose \(\displaystyle 1000\), because there is a set of \(\displaystyle 3\) numbers that make the repeating decimal. To determine the value to multiply the repeating decimal, we do \(\displaystyle 10\) to the power of number in a set before it repeats.

Now we have:

\(\displaystyle 857.857857857...=1000x\) 

Lets subtract this equation with the first one and we get:

\(\displaystyle 999x=857\) We do this because we want to get rid of the repeating decimals and now we have a simple equation, isolate \(\displaystyle x\) and we arrive at the final answer. 

Example Question #1 : Simplifying Fractions

Rewrite the mixed fraction \(\displaystyle 6\frac{12}{15}\) as an improper fraction in lowest terms, and call \(\displaystyle N\) the product of the numerator and the denominator of the simplified improper fraction. How many digits does \(\displaystyle N\) have?

Possible Answers:

\(\displaystyle 5\)

\(\displaystyle 6\)

\(\displaystyle 2\)

\(\displaystyle 4\)

\(\displaystyle 3\)

Correct answer:

\(\displaystyle 3\)

Explanation:

\(\displaystyle \frac{12}{15} = \frac{12 \div 3}{15 \div 3} = \frac{4}{5}\), so \(\displaystyle 6\frac{12}{15}\) simplifies to \(\displaystyle 6\frac{4}{5}\).

The numerator of the improper form of a mixed fraction is the original numerator added to the product of the integer and the original denominator. The new denominator is the same as the old one. Therefore, 

\(\displaystyle 6\frac{4}{5} = \frac{6 \times 5 + 4}{5} = \frac{30+4}{5} = \frac{34}{5}\) 

Multiply the numerator and the denominator: \(\displaystyle 34 \times 5 = 170\),

a three-digit number.

Example Question #2 : Simplifying Fractions

Reduce \(\displaystyle \frac{16}{60}\) to lowest terms, call \(\displaystyle N\) the sum of the numerator and the denominator. Which statement is true of \(\displaystyle N\)?

Possible Answers:

\(\displaystyle 30 < N \le 35\)

\(\displaystyle 20 < N \le 25\)

\(\displaystyle 15 < N \le 20\)

\(\displaystyle 10 < N \le 15\)

\(\displaystyle 25 < N \le 30\)

Correct answer:

\(\displaystyle 15 < N \le 20\)

Explanation:

\(\displaystyle \frac{16}{60} = \frac{16 \div 4}{60 \div 4} = \frac{4}{15}\)

Add the numerator and the denominator: \(\displaystyle 4+15= 19\)

The correct response is therefore \(\displaystyle 15 < N \le 20\).

Example Question #1 : How To Simplify A Fraction

Consider a fraction \(\displaystyle \frac{N}{65}\), where the numerator is unknown. How many of the following values of \(\displaystyle N\) would yield a fraction not in lowest terms?

I) \(\displaystyle N = 115\)

II) \(\displaystyle N = 116\)

III) \(\displaystyle N = 117\)

IV) \(\displaystyle N = 118\)

Possible Answers:

\(\displaystyle \textup{Four}\)

\(\displaystyle \textup{None}\)

\(\displaystyle \textup{Two}\)

\(\displaystyle \textup{One}\)

\(\displaystyle \textup{Three}\)

Correct answer:

\(\displaystyle \textup{Two}\)

Explanation:

The prime factorization of \(\displaystyle 65\) is \(\displaystyle 5 \times 13\), so the fraction \(\displaystyle \frac{N}{65}\) is reducible if and only if \(\displaystyle N\) is a multiple of 5 or 13.

We can immediately tell that 115 is the only multiple of 5, so we test the other numbers to see if there is a multiple of 13. We soon see that

\(\displaystyle 117 \div 13 = 9\), so 116 and 118 cannot be multples of 13.

115 and 117 are the only values of \(\displaystyle N\) that yield reducible fractions, so the correct response is two.

Example Question #1 : How To Simplify A Fraction

Reduce the fraction \(\displaystyle \frac{39}{111}\) to lowest terms, and call \(\displaystyle N\) the product of the numerator and the denominator of the simplified fraction. Give the value of \(\displaystyle N\).

Possible Answers:

\(\displaystyle 507\)

\(\displaystyle \text{The correct answer is not among the other choices.}\)

\(\displaystyle 444\)

\(\displaystyle 429\)

\(\displaystyle 481\)

Correct answer:

\(\displaystyle 481\)

Explanation:

\(\displaystyle \frac{39 \div 3}{111 \div 3} = \frac{13}{37}\)

Multiply the numerator and the denominator: \(\displaystyle 13 \times 37 = 481\)

The product is a three-digit number.

Example Question #1 : How To Simplify A Fraction

Put the fraction in the simplest form.

\(\displaystyle \frac{24}{36}\)

Possible Answers:

\(\displaystyle \frac{12}{18}\)

\(\displaystyle \frac{2}{3}\)

\(\displaystyle \frac{4}{6}\)

\(\displaystyle \frac{8}{12}\)

Correct answer:

\(\displaystyle \frac{2}{3}\)

Explanation:

To put a fraction in simplest form, keep dividing the numerator and denominator by the same number until you cannot go any further.

\(\displaystyle \frac{24\div2}{36\div2}=\frac{12}{18}\)

\(\displaystyle \frac{12\div2}{18\div2}=\frac{6}{9}\)

\(\displaystyle \frac{6\div3}{9\div3}=\frac{2}{3}\)

Example Question #2 : How To Simplify A Fraction

Put the fraction in simplest form.

\(\displaystyle \frac{224}{400}\)

Possible Answers:

\(\displaystyle \frac{28}{50}\)

\(\displaystyle \frac{56}{100}\)

\(\displaystyle \frac{14}{25}\)

\(\displaystyle \frac{25}{14}\)

Correct answer:

\(\displaystyle \frac{14}{25}\)

Explanation:

To simplify a fraction, divide both the numerator and the denominator by the same numbers until there is no number that can divide them both without resulting in a remainder.

\(\displaystyle \frac{224\div4}{400\div4}=\frac{56\div2}{100\div2}=\frac{28\div2}{50\div2}=\frac{14}{25}\)

Example Question #3 : How To Simplify A Fraction

Put the fraction in simplest form.

\(\displaystyle \frac{36}{120}\)

Possible Answers:

\(\displaystyle \frac{3}{120}\)

\(\displaystyle \frac{10}{3}\)

\(\displaystyle \frac{6}{20}\)

\(\displaystyle \frac{3}{10}\)

Correct answer:

\(\displaystyle \frac{3}{10}\)

Explanation:

To simplify a fraction, divide both the numerator and the denominator by the same numbers until there is no number that can divide them both without resulting in a remainder.

\(\displaystyle \frac{36 \div 12}{120 \div 12}=\frac{3}{10}\)

Learning Tools by Varsity Tutors