We call a number a mountain number if its middle digit is larger than any other digit.  For example, 284 is a mountain number.  How many 3-digit mountain numbers are there?
Question:
We call a number a mountain number if its middle digit is larger than any other digit.  For example, 284 is a mountain number.  How many 3-digit mountain numbers are there?
Answer:
Let's think step by step.

user
240
We call a number a mountain number if its middle digit is larger than any other digit.  For example, 284 is a mountain number.  How many 3-digit mountain numbers are there?
train