142
1•4= 4
5•5= 25
1•11= 11
6•18= 102
102+11+25+4= 142
Answer:

Step-by-step explanation:
7x + 24x = 25 x
31 x = 25 x
Subtracting 25x to both sides
31x - 25x = 0
6x = 0
Dividing both sides by 6
=> x = 0
12 pm to 4 pm = 4 hours, 1 hour is 60 rotations, thus: 4*60=240 Rotations.