30/7 +30/7=60/7
60/7-22/7=38/7
59/7 -38/7=21/7
21/7 -19/7=2/7
18/24 can both be divided by 6, so it's 3/4
Eight units I'm pretty sure
<h3>
Answer:</h3>
<h3>
Step-by-step explanation:</h3>
If Alex cut his wire 18 times, he ended up with 19 equal pieces. He kept 7, so has 7/19 of his 1/3 of the wire.
Bob cut his wire 20 times, so ended up with 21 pieces, of which he kept 9. So he has 9/21 = 3/7 of his 1/3 of the wire.
Claudia kept 1/13 of her 1/3 of the wire, so has the smallest piece.
Bob kept (3/7)·(1/3)·126 cm = 18 cm.
Alex kept (7/19)·(1/3)·126 cm ≈ 15.47 cm.
Bob kept the longest part of the original wire.
The number that is not irrational is
. The correct option is the second option 
<h3>
Irrational numbers </h3>
From the question, we are to determine which of the given options is not irrational
Irrational numbers are the set of real numbers that cannot be expressed in the form of a fraction, p/q, where p and q are integers.
is a repeating decimal and it can be expressed as a fraction

∴
is not an irrational number. It is a rational number
The other options cannot the expressed as a fraction.
Hence, the number that is not irrational is
. The correct option is the second option 
Learn more on Irrational numbers here: brainly.com/question/11919233
#SPJ1