Question

How many numbers are there between $500$ and $600$ in which $9$ occurs only once?

• A. $18$
• B. $19$
• C. $20$
• D. $21$

Answer 1

The correct option is A $18$

$509,519,529,539,549,559,569,579,589,590,591,592,593,594,595,596,597,598$ are the numbers between $500$ and $600$

$599$ will not be counted because $9$ is occuring twice in that number.So there are total $18$ numbers between $500$ and $600$ in which $9$ occur only once.