How many four-digit integers exist such that all their digits are even?  Select:  A) 80  B) 100  C) 120  D) 125  E) 500
0 is also an even integer   so last digit can be filled in 5 ways- 0,2,4,6,8   for both second and third digit there are 5 possibilities-   5 X 5 X 5 X 5 = 625   _______________   The first digit can be any of the four: 2, 4, 6, or 8. For both second, third and four digits, there are 5 possibilities. The answer is 4∗5∗5*5=500.   The correct answer is 500
<result>E</result>
How many four-digit integers exist such that all their digits are even?