Answer:
55 cm
Step-by-step explanation:
Let x = the length of the first piece of rope.
The three pieces together equal 142 cm.
The length of the first piece is x cm.
The length of the second piece is x/2 cm, because it is half as long as the first piece.
The length of the third piece is x-3 cm.
Now, add all pieces up to equal 142.
x + x/2 + x - 3 = 142
2x + x/2 -3 = 142
2.5x - 3 = 142
2.5x = 145
x = 58
The first piece of rope is 58 cm.
If the third piece of rope is 3 cm less, then it is 58 - 3 cm, which is 55 cm.
