Answer:
$ 20
Explanation:
Given that,
No. of notes Joe has = 4
The total value of the notes = $ 75
From the given notes, 4 notes that can make the sum of 75 would be
$ 50 note + $ 10 + $ 10 note + $ 5
= 50 * 1 + 10 * 1 + 10 * 1 + 5 * 1
= $ 75
Thus, the note that would not be included in the total value would $20 note as if we add it either the sum would be greater or lesser with four notes in combination.