Question

If rain film 20 mm/m how much did it fall into in millimeters per hour

Answer 1

1 min = $\frac{1}{60} \: hour$

Now,

Replacing m with $\frac{1}{60} h$

$\frac{20mm}{m} \\ \frac{20mm}{ \frac{1}{60}h } \\ \frac{20mm \times 60}{1h} \\ \frac{1200mm}{h}$

Here it is,
20mm/m = 1200 mm/h