2017 AMC 10B Problems/Problem 17
Problem
Call a positive integer monotonous if it is a one-digit number or its digits, when read from left to right, form either a strictly increasing or a strictly decreasing sequence. For example, , , and are monotonous, but , , and are not. How many monotonous positive integers are there?
Solution
by e_power_pi_times_i
It adds in at the end, but we know since it is MAA, it is probably a troll question, so we look at the answers. looks likely, as it is just , but we remember that MAA is trolly so it is probably .
See Also
2017 AMC 10B (Problems • Answer Key • Resources) | ||
Preceded by Problem 16 |
Followed by Problem 18 | |
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