The correct answer is the third one.
However, i would suggest you to remember the following simple rule:
Answer:
thanks
Step-by-step explanation:
First piece is x
second piece is y. y=4x
third piece is z. z=3y=12x
x+y+z=680
x+4x+12x=680
17x=680. x=40cm y=160cm. z=480cm
Say you have 95 over 10. You put how many times 10 goes into 95, which is 9. Then you have 5 left over. You take 5 and put it over 10. You can simplify that to 1 over 2. Your mixed number would then be 9 and 1/2.