Question

find the rule and complete the table.
in\tout
15\t3
20
25\t5
50\t10
\t15
80\t16

Explanation:

Step1: Find the rule

By observing the given pairs (15, 3), (25, 5), (50, 10), (80, 16), we can see that the rule is to divide the "In" number by 5 to get the "Out" number. That is, if the "In" number is $x$, the "Out" number is $\frac{x}{5}$.

Step2: Find the missing "Out" value for "In" = 20

Using the rule $\frac{x}{5}$, when $x = 20$, we have $\frac{20}{5}=4$.

Step3: Find the missing "In" value for "Out" = 15

Let the missing "In" value be $y$. Since $\frac{y}{5}=15$, then $y = 15\times5=75$.

Answer:

The missing values are 4 in the "Out" - column for "In" = 20 and 75 in the "In" - column for "Out" = 15.