Find the rate in which both balls make one full rotation around the track.
Ball A:

It takes 30 seconds for Ball A to make a full rotation.
Ball B:

It takes 20 seconds for Ball B to make a full rotation.
Find the least common multiple of 20 and 30 to find the time at which they'll meet.
Multiples of 20: {20,40,60}
Multiples of 30: {30,60}
60 is the least common multiple of both 20 and 30.
The balls will meet again at
60 seconds.
Answer:
1100 minutes
Step-by-step explanation:
Equation: 35=.05x-20
Why? x is the amount of minutes on his phone. Each minute is 0.05 hence 0.05x. Subtract 20 because that is the flat rate
55=.05x
x=1100
Therefore he was on his phone for 1100 minutes
Ok so you would just take the two fractions and simply if needed and that the answer!
The line is 4 units in length.