Farthest fraction
Which of these fractions is the largest?
Problem
Which is the largest of these fractions?
$$\frac{7}{15} \qquad \frac{4}{9} \qquad \frac{5}{11}$$
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
Student Solutions
Answer: $\frac7{15}$
All three fractions are just under $\frac{1}{2}$.
$\frac{7}{15}$ is $\frac{1}{2}-\frac{1}{30}$
$\frac{4}{9}$ is $\frac{1}{2}-\frac{1}{18}$
$\frac{5}{11}$ is $\frac{1}{2}-\frac{1}{22}$
So $\frac{7}{15}$ is the largest.