Question

which one doesn’t belong? which expression does not belong with the other three? $2\frac{5}{8}$ $\frac{8}{8}+\frac{8}{8}+\frac{5}{8}$ $\frac{20}{8}$ $\frac{16}{8}+\frac{5}{8}$

Explanation:

Step1: Convert mixed number to improper fraction

To convert \( 2\frac{5}{8} \) to an improper fraction, we use the formula \( a\frac{b}{c}=\frac{a\times c + b}{c} \). So, \( 2\frac{5}{8}=\frac{2\times8 + 5}{8}=\frac{16 + 5}{8}=\frac{21}{8} \).

Step2: Calculate the sum of the second expression

For \( \frac{8}{8}+\frac{8}{8}+\frac{5}{8} \), we add the numerators: \( \frac{8 + 8+5}{8}=\frac{21}{8} \).

Step3: Simplify the third expression

\( \frac{20}{8} \) can be simplified, but its value is \( \frac{20}{8}=\frac{5}{2}=2.5 \), while the other expressions (after calculation) are \( \frac{21}{8}=2.625 \).

Step4: Calculate the sum of the fourth expression

For \( \frac{16}{8}+\frac{5}{8} \), we add the numerators: \( \frac{16 + 5}{8}=\frac{21}{8} \).

Answer:

\( \frac{20}{8} \) does not belong with the other three because \( 2\frac{5}{8}=\frac{21}{8} \), \( \frac{8}{8}+\frac{8}{8}+\frac{5}{8}=\frac{21}{8} \), \( \frac{16}{8}+\frac{5}{8}=\frac{21}{8} \), and \( \frac{20}{8}
eq\frac{21}{8} \). So the expression that doesn't belong is \( \frac{20}{8} \).