John has to restring 3 basses with 4 strings each, twice as many guitars which have 6 strings each, and 3 fewer 8 string guitars than the normal guitars. How many strings does he need? Think carefully first, then make a decision:
The basses take 3 * 4 = 12 strings. He restrings 2 * 3 = 6 normal guitars. That takes 6 * 6 = 36 strings. He restrings 6 - 3 = 3 guitars with 8 strings. So that uses 3 * 8 = 24 strings. So he uses 12 + 36 + 24 = 72 strings. So, the answer is 72.