What is the minimum weighs, how can you find out which apple is bad?

Question

Debbie has a lot more apples to check. Now she has 5 apples. Four apples are good,  weighing the same. But the bad one either weighs more or less than the others. List the process steps and decision you need to make in order to determine which apple is bad,  and whether it is heavier or lighter than the good ones. 

 

 

You know one of the apples is either heavier or lighter than the others,  what are the minimum ways needed to determine which apple is bad,  and whether it is lighter or heavier than the others. 

Answer 1

Step 1. Place 4 apples on the balance 1 2 3 4. Leave out apple 5
If balanced, then apple 5 is bad.
Leave apple 1, place apple 5, and compare. Apple 5 will be lighter or heavier than apple 1.

Step 2 Place apples on the balance 1 2 3 4
If unbalanced, then apple 5 is a good apple.

Remove apples 2 and 3, leaving apples 1 4 on the balance.
If balanced, then remove both apples, and replace them with apples 2 and 5.
If unbalanced, you will know if apple 2 is lighter or heavier than apple 5.
If balanced, then apple 3 is the bad apple.
Remove apple 2, and replace it with apple 3 to determine if it is lighter or heavier.

If apples 1 4 are not balanced, replace apple 4 with apple 5.
If balanced, then apple 4 is bad. If not, then you will know if apple 1 is lighter or heavier.
Finally, compare apple 4 with apple 5.