Answer: 0.645 g/ml
Explanation: 
To calculate density of a substance, we use the equation: 
 
 
We are given: 
mass of gasoline = 1.29 kg = 1290 g 

Volume of gasoline = 2 L =2000 ml 
 
 
Putting values in above equation, we get: 
 
 
Hence, the density of gasoline in g/ml is 0.645.