I need more information in order to solve it
        
             
        
        
        
Answer: -iSimplify the expression using the definition of an imaginary number  
i
=
√
−
1
.
−
i
Step-by-step explanation: Simplify the expression using the definition of an imaginary number i
=
√
−
1
.
−
i
 
        
             
        
        
        
Alright, lets get started.
Suppose first mechanic charges= x 
So, second mechanic charges will be =  (because total of their rates was 125)
 (because total of their rates was 125)
first mechanic worked for 5 hours, and the second mechanic worked for 15 hours and together they charged a total of $1225
Means 



Adding 10 x in both sides

Subtracting 1225 from both sides

Dividing 10 in both sides

x = 65
For second mecahnics rate = 125 - 65 = 60
Hence The mechanic who worked 5 hours charged $ 65 per hour, the one who worked 15 hours charged $ 60 per hour: Answer
Hope it will help :)
 
        
             
        
        
        
Answer:
~ 639.75 cm^3
Step-by-step explanation:
see pic
<h2>
Edit: I did this with the assumption that 12 was the diameter, if it's the radius disregard this please</h2>