GATE Electrical 2019 | GA Question: 6

Question

How many integers are there between $100$ and $1000$ all of whose digits are even?

• A. $60$
• B. $80$
• C. $100$
• D. $90$ 

Answer 1

_ _ _ 

1. In the units place the possible number can be vary from 0,2,4,6,8 
2. In the tens place similarly, outcome is the same as number can vary from 0 to 8
3. But the story is not the same in case of hundredth place as number should be greater than 100 thus the only possible outcome is 2,4,6,8 
4.  So 4*5*5 = 100 possibilities are there in which all the digits can be even.