1.0 link Rainbow Dash Network http://rainbowdash.net/ Narwhal (narwhal) http://rainbowdash.net/narwhal http://rainbowdash.net/notice/3641572 @<span class="vcard"><a href="http://rainbowdash.net/user/33432" class="url" title="rainbowcrash"><span class="fn nickname mention">purplebear</span></a></span> The GCF is 5. 1345/2860 =&gt; 269/572. For that second part the LCM of 1, 2, 3, 4, 5 is 60, which is problematic because 60 is also divisible by 6 and therefore any number with factors of 1, 2, 3, 4, and 5 can also go evenly into 6.