If MERCK, MARS & AIG merged and became an art supplies company, they would sell ___

MAGICMARKERS

Think of a colorful writing tool whose name combines the first letters of three famous corporations.

This clue plays on the first letters of three well-known companies: Merck (M), Mars (A), and AIG (G). When you combine those letters with "IC" (sounding like "ink") and "MARKERS" (a common art supply), you get "MAGIC MARKERS," a brand of colorful pens. The joke is imagining these corporate giants teaming up to sell something totally unrelated—like art supplies—just by mashing up their initials.