Answer:

Step-by-step explanation:

Apply rule 

Multiply the numbers: 

Answer:
380
Step-by-step explanation:
280 coffe machine
15 bag multiple for 40= 600 - 15%= 540
540+280=820
1200-820=380
Answer:
75
Step-by-step explanation:
Just make the number of regular gasoline sold to be x, while the number of premium gasoline sold to be (550-x).
That's all.
And goodluck.