How many tornadoes the digit 3 occur at ten's place in natural from 10

1.	How many tornadoes the digit 3 occur at ten's place in natural from 100 to 1000?
Answer» Step-by-step explanation:Let’s suppose XY3 is a 3 digit number with 3 in unit’s place Number of ways X can be filled = 9 (1–9 numbers excluding 0 as it is a 3 digit number). Number of ways Y can be filled = 10 (0–9 numbers) TOTAL number of numbers with 3 in unit’s place = 910 = 90 STEP2 - Now, let’s suppose X3Y is a 3 digit number with 3 in ten’s place. Number of ways X can be filled = 9 (1–9 numbers excluding 0 as it is a 3 digit number). Number of ways Y can be filled = 9 (0–9 numbers excluding 3 as we are counting this in Step1) Total number of numbers with 3 in ten’s place = 99 = 81 So, number of times 3 occurs in ten’s and unit’s place from 100 to 1000 = 90+81 = 171.

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