Identify which example constitutes consideration for purposes of determining a valid contract.

Question $32$ options:

The famous tenor, Luciano Pasta agrees to sing at La Scala Opera House for $$150,000\mathrm{.}00.$ Luciano later changes his mind and refuses to sing unless he is paid $$200,000\mathrm{.}00.$ The promoter only pays $$150,000.$ Luciano is rightfully owed another $$50,000\mathrm{.}00$

Image result for photo of la scala

Ronald saves a drowning swimmer named Vicki. Vicki's grandmother promises to pay Ronald $$10,000$ for his good deed. Later, she refuses to pay.

I promise to pay you $$50,000$ if you kill my ex$-$husband.

None of these examples demonstrate valid consideration.