She has memorized 15 of the words, which is three-fifths of the list. how many words are on the list?

She memorized three-fifths of the list, we can write the proportion as
memorized words : total words = 3 : 5

Find words on the list
total = proportion of total/proportion of memorized × the memorized words
total = 5/3 × 15
total = 25

The words on the list are 25

It is the top one. the answer is -7. that is smallest