Art of Problem Solving
AoPS Online
Math texts, online classes, and more
for students in grades 5-12.
Visit AoPS Online ‚
Books for Grades 5-12 Online Courses
Beast Academy
Engaging math books and online learning
for students ages 6-13.
Visit Beast Academy ‚
Books for Ages 6-13 Beast Academy Online
AoPS Academy
Small live classes for advanced math
and language arts learners in grades 2-12.
Visit AoPS Academy ‚
Find a Physical Campus Visit the Virtual Campus

2007 AMC 8 Problems/Problem 18

$303\times505=153015$

The ones digit plus thousands digit is $5+3=8$.

$30303\times50505=1530453015$

Note that the ones and thousands digits are, added together, $8$. (and so on...) So the answer is $\boxed{D}$ $(8)$.

Retrieved from "https://artofproblemsolving.com/wiki/index.php?title=2007_AMC_8_Problems/Problem_18&oldid=39358"