After completing a 10 hour walk, chester snowman goes inside to get warm. as he sits by the fire, he starts to melt at a rate of 3 inches per hour. starting at the height he reached at the end of his walk, determine chester's height after sitting by the fire for 10 hours.

We can't tell you the height after sitting by the fire
for 10 hours, because you didn't tell us the height
he reached at the end of his walk.

All we can tell you is that whatever his height was
when he came in to get warm, it's

             (10 hours) x (3 inches/hour)  =  30 inches

shorter after 10 hours by the fire.