Answer:
0.5 inches per month
Step-by-step explanation:
There are nearly 0.3937 inches in 1 cm, so
[tex]1 \ cm \approx 0.03937 \ in\\ \\15\ cm\approx 5.9055\ in[/tex]
There are 12 months in the year, so'
15 centimeters per year is equivalent to
[tex]15 \ cm/year\approx \dfrac{5.9055}{12}\ in/month\\\approx 0.492125\ in/month\\\approx 0.5\ in/month\\\\[/tex]