Final answer:
The heavier instruments should be placed on the bottom when assembling a set containing heavy and delicate instruments to provide stability and prevent damage.
Step-by-step explanation:
When assembling a set containing heavy and delicate instruments, the heavier instruments should be placed on the bottom. Placing the heavier instruments on the bottom ensures that the weight is evenly distributed and provides stability to the set. This prevents the delicate instruments from being damaged or toppling over.
For example, when stacking books of different weights, the heavier books should be placed at the bottom to prevent the stack from toppling.