How many positive even integers less than 100 contain digits 4 or 7?
How many positive even integers less than 100 contain digits 4 or 7?
Answer/Solution
18
Steps/Work
One digit numbers: 4
Two digit numbers:
4 at tens place: 40,42,44,46,48
7 at tens place: 70,72,74,76,78
4 at units place: 14,24,34,54,64,84,94 (duplicates removed)
If 7 is at units place, the number cant be even
Total:1+5+5+7= 18
Answer C
Two digit numbers:
4 at tens place: 40,42,44,46,48
7 at tens place: 70,72,74,76,78
4 at units place: 14,24,34,54,64,84,94 (duplicates removed)
If 7 is at units place, the number cant be even
Total:1+5+5+7= 18
Answer C