Question

位于 $\dfrac{1}{6}$ 和 $\dfrac{1}{4}$ 正中间的数是

The number halfway between $\dfrac{1}{6}$ and $\dfrac{1}{4}$ is

$\dfrac{1}{10}$

$\dfrac{1}{5}$

$\dfrac{5}{24}$

$\dfrac{7}{24}$

$\dfrac{5}{12}$

两个数正中间的数是它们的平均数： $\dfrac{\frac16 + \frac14}{2}$ 。

因为 $\dfrac16 + \dfrac14 = \dfrac{2}{12} + \dfrac{3}{12} = \dfrac{5}{12}$ ，所以平均数是 $\dfrac{5}{12} \div 2 = \dfrac{5}{24}$ 。

所以正确答案是 C。

The number halfway between two values is their average: $\dfrac{\frac16 + \frac14}{2}.$

Since $\dfrac16 + \dfrac14 = \dfrac{2}{12} + \dfrac{3}{12} = \dfrac{5}{12},$ the average is $\dfrac{5}{12} \div 2 = \dfrac{5}{24}.$

Thus, the correct answer is C .