When positive integer v is multiplied by positive integer n, the units digit of the product is 3. Which of the following are factors of n?
I. 8
II. 15
III. 30	Choose the correct option
A) I only
B) II only
C) I and II only
D) II and III only
E) None of the above
ans E..   we can tell the ans w/o using examples..   the units digit of product v*n is 3..   this means v and n are odd positive integers..   therefore n cannot have an even factor so 8 and 30 are out..   n cannot have a factor ending in 5 because in that case the units digit has to be 5 or 0... so 15 is also out
<result>E</result>
When positive integer v is multiplied by positive integer n, the units digit of the product is 3. Which of the following are factors of n?
I. 8
II. 15
III. 30