VVKISVTIKSG
LLKISLTIILI

The bottom one is a helix, so the top one is always the better strand...

VVTTVVTTVVTT
VTVTVTVTVTVT

Bottom one is nicely in-out-in-out. Whoever does this wrong at the examination will come back next year...

VVICFFWIIFVI
VKICFKSIYVRI

Top one is totally hydrophobic. That never happens (not even in membrane proteins).

VKITFEITVEIR
IRVTWRGTINIE

Bottom one has a G and an N and those two are always bad for strand (and also bad for helix, by the way).