Question

how many times does 2 occur in tens and units place in the ​

Answer 1

Answer:

Total number of numbers with 2 in ten's place = 9*9 = 81. So, number of times 2 occurs in ten's and unit's place from 100

Answer 2

Answer:

SEE THIS EXAMPLE

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 = 9*10 = 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 = 9*9 = 81

So, number of times 3 occurs in ten’s and unit’s place from 100 to 1000 = 90+81 = 171.