35%.
42/120 = 0.35.
0.35 X 100 = 35. That tells us 42 is 35% of 120.
Answer:
8 is your answer
Step-by-step explanation:
Hope this helps sorry if I'm wrong
Let's use the variable x to represent the length of the first and second pieces.
If the third piece has twice the length of the first and second, its length is 2x.
If the fourth piece has half the length of the first and second, its length is 0.5*x.
Adding all four pieces and equating to 54 inches, we have:

So the length of each piece is:
12 inches, 12 inches, 24 inches and 6 inches.
First subtract the 7 from both sides and that would equal 2x+9=2x then subtract 2x and the answer is 9