SSAT Upper Level Quantitative - How to find the decimal equivalent of a fraction

Simplify and express as a decimal:

$\frac{4\frac{2}{3}}{5\frac{3}{5}}$

$0.8\overline{3}$

$0.\overline{8}$

Explanation

$\frac{4\frac{2}{3}}{5\frac{3}{5}} = 4\frac{2}{3} \div 5\frac{3}{5} = \frac{14}{3} \div \frac{28}{5} = \frac{14}{3} \times \frac{5} {28} = \frac{1}{3} \times \frac{5} {2} = \frac{5}{6}$

$\frac{5}{6}= 5 \div 6 = 0.8333...$ ,

so the correct response is $0.8\overline{3}$ .

Which of the following fractions is closest to 0.6?

$\frac{5}{8}$

$\frac{4}{7}$

$\frac{9}{16}$

$\frac{2}{3}$

$\frac{13}{20}$

Explanation

For each fraction, divide each numerator by its denominator to get its decimal representation, then subtract to find its difference from 0.6.

$\frac{4}{7} \approx 0.5714 ; 0.6 - 0.5714 =0.0286$

$\frac{5}{8}=0.625; 0.625-0.6 = 0.025$

$\frac{9}{16} = 0.5625; 0.6-0.5625=0.0375$

$\frac{2}{3}\approx 0.6667; 0.6667-0.6=0.0667$

$\frac{13}{20} = 0.65; 0.65-0.6=0.05$

$\frac{5}{8}$ is the closest to 0.6 of the five.

Which of the following falls between 0.32 and 0.33?

$\frac{25}{77}$

$\frac{24}{77}$

$\frac{23}{77}$

$\frac{26}{77}$

$\frac{27}{77}$

Explanation

Since all of the fractions have 77 as a denominator, one way to solve this problem is to let be the numerator of the correct fraction. Therefore, the equivalent problem is to find integer such that

$0.32 < \frac{N}{77} < 0.33$

Multiply each expression by :

$0.32 \cdot 77 < \frac{N}{77} \cdot 77 < 0.33 \cdot 77$

Therefore, , making $\frac{25}{77}$ the correct choice.

Which of the following is a true statement?

$-0.71< -\frac{19}{27}< -0.70$

$-0.72< -\frac{19}{27}< -0.71$

$-0.73< -\frac{19}{27}< -0.72$

$-0.74< -\frac{19}{27}< -0.73$

$-0.75< -\frac{19}{27}< -0.74$

Explanation

Divide 19 by 27:

Division

$0.70 < \frac{19}{27}< 0.71$ ,

$-0.71< -\frac{19}{27}< -0.70$ .

Express $\frac{8}{15}$ as a decimal.

$0.5\overline{3}$

$0.5\overline{8}$

$0.\overline{5}$

Explanation

Divide 8 by 15:

$\frac{8}{15} = 8 \div 15 = 0.5333...$

The 3 repeats, so the correct choice is $0.5\overline{3}$ .

Let $a =3 \frac{3}{5}$ and $b=1 \frac{5}{6}$

Which of the following is closest to ?

Explanation

$a - b = 3\frac{3}{5} - 1\frac{5}{6}$

$= \frac{18}{5} - \frac{11}{6}$

$= \frac{18\times 6 }{5 \times 6} - \frac{11\times 5}{6\times 5}$

$= \frac{108}{30} - \frac{55}{30}$

$= \frac{53}{30}$

$= 53 \div 30 \approx 1.77$

The correct choice is 1.8.

Define an operation $\blacklozenge$ as follows:

For all real numbers :

$a\blacklozenge b = a^{2} - b^{2}$

Which of the following is closest to $\frac{1}{2} \blacklozenge \frac{1}{3}$ ?

Explanation

$a\blacklozenge b = a^{2} - b^{2}$

$\frac{1}{2} \blacklozenge \frac{1}{3} =\left ( \frac{1}{2} \right ) ^{2} - \left ( \frac{1}{3} \right )^{2}= \frac{1}{4} - \frac{1}{9}= \frac{9}{36} - \frac{4}{36}= \frac{5}{36}$

$= 5 \div 36 = 0.13888...$

The correct choice is 0.15.

Define an operation $\blacklozenge$ as follows:

For all real numbers :

$a\blacklozenge b = \frac{ab}{a+b}$

Which of the following is equal to $\frac{1}{2} \blacklozenge \frac{1}{3}$ ?

$0.\overline{2}$

$0.1\overline{6}$

The correct answer is not among the other choices.

Explanation

$a\blacklozenge b = \frac{ab}{a+b}$

$\frac{1}{2} \blacklozenge \frac{1}{3}=\frac{\frac{1}{2} \times \frac{1}{3}}{\frac{1}{2} +\frac{1}{3}}=\frac{\frac{1}{6} }{\frac{5}{6} } = \frac{1}{6} \div \frac{5}{6} = \frac{1}{6} \times \frac{6} {5} = \frac{1}{1} \times \frac{1} {5} = \frac{1}{5}$

$\frac{1}{5} = 1 \div 5 = 0.2$ ,

is the correct response.

Let $a =1 \frac{4}{9}$ , $b = 1\frac{3}{8}$ , and $c= \frac{1}{2}$ .

Which of the following is closest to ?

Explanation

$a bc=1 \frac{4}{9} \times 1\frac{3}{8} \times \frac{1}{2}= \frac{13}{9} \times \frac{11}{8} \times \frac{1}{2}= \frac{143}{144}= 143 \div 144 \approx 0.99$