How many 3-digit numerals begin with a digit that represents a prime and end with a digit that ...
How many 3-digit numerals begin with a digit that represents a prime and end with a digit that represents a odd prime number?
Answer/Solution
120
Steps/Work
prime digits 2,3,5 and 7.
three digit numbers _ _ _
1st place can be filled in 4 ways
2nd place can be filled in 10 ways
3rd place can be filled in 3 ways
Total=4*10*3=120
Ans : B
three digit numbers _ _ _
1st place can be filled in 4 ways
2nd place can be filled in 10 ways
3rd place can be filled in 3 ways
Total=4*10*3=120
Ans : B