Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you:
You have to remember the あ portion of this word to read it. What is the correct answer that will give you a success? It is the first answer, A (あ).
The odds of winning the lottery are very low.
Such a weak-hit grounder can't be a hit.
The party I threw for my father’s 50th birthday was a success and he even found a new girlfriend there.