This looks like a test's question. Anyway, you DO know where the primers are, in fact they are underlined. I counted 62 bases per line, thus you got: (62-5)+62+(62-11). Assuming counting issues due to the fact that the sequence in an image, I would go for the closest to this calculation.
primers here are underlined. length of the amplicon will thereby be from 1st base of the upper to the last of the lower. it will additionally be in bp, not in kbp.