Strictly increasing three-digit numbers
How many 3-digit numbers have digits that are strictly increasing from left to right (for example 137, but not 122 or 321)?
Show hints (2)+
- A strictly increasing order is unique, so counting the numbers = counting which 3 digits appear.
- 0 can never appear (it would have to lead); choose 3 from : .
Answer
Reveal answer →Final answer
84
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Asked at: Data-Driven Research, Options Market-Making