Mr. President, it is natural to man to indulge in the illusions
of hope. We are apt to shut our eyes against a painful truth,
and listen to the song of that siren, till she transforms us
into beasts. Is this the part of wise men, engaged in a
great and arduous struggle for liberty? Are we disposed to
be of the number of those, who, having eyes, see not, and
having ears, hear not, the things which so nearly concern
their temporal salvation? For my part, whatever anguish of
spirit it may cost, I am willing to know the whole truth; to
know the worst, and to provide for it.
What is most likely the author's purpose in this section of the speech?
to inspire citizens to take up arms and fight

this might :

18≥1.5x

then you're going to want to divide 18 by 1.5. this equals 12. so the answer would be 12.

aka, you can buy 12 peppers, at most.

the third paragraph is your answer,

"but, in a larger sense, we can not dedicate — we can not consecrate — we can not hallow — this ground. the brave men, living and dead, who struggled here, have consecrated it, far above our poor power to add or detract. the world will little note, nor long remember what we say here, but it can never forget what they did here. it is for us the living, rather, to be dedicated here to the unfinished work which they who fought here have thus far so nobly advanced. it is rather for us to be here dedicated to the great task remaining before us— that from these honored dead we take increased devotion to that cause for which they gave the last full measure of devotion—that we here highly resolve that these dead shall not have died in vain—that this nation, under god, shall have a new birth of freedom—and that government of the people, by the people, for the people, shall not perish from the earth. "