To find the slope, we use the formula for slope,
[tex]m=\frac{y_{2}-y_{2}} {x_{2}-x_{1}}[/tex]
Letting the point (2,5) be [tex](x_{1},y_{1})[/tex] and the point (4,10) be [tex](x_{2},y_{2})[/tex].
Now plugging in these values in the formula for slope, we get,
[tex]m=\frac{10-5}{4-2} =\frac{5}{2}[/tex]. The slope is [tex]\frac{5}{2}[/tex].
This basically means 5 mm of rain falls in every 2 hours, or 2.5 mm of rain falls every hour ([tex]\frac{5}{2} =2.5[/tex])
ANSWER: Slope is [tex]\frac{5}{2}[/tex] and 5 mm of rain falls every 2 hours.