Answer: 720 ways
Step-by-step explanation:
Given
A train has 1 main engine and remaining 6 train cars
If the engine is always in the front the remaining train cars can be arranged is

Answer: In the last steps, instead of multiply each side by 3, he has to divide each side by 3.
Step-by-step explanation:
Hi, Tobin makes the mistake in the last steps.
3(x-1.25) = 11.25
3x-3.75= 11.25
3x-3.75+3.75= 11.25+3.75
3x = 15
Until this step is the work ok.
Now, instead of multiply each side by 3, he has to divide each side by 3:
So:
3x /3 = 15/3
x = 5
Feel free to ask for more if needed or if you did not understand something.
Answer:
Total bill = $88.50
Step-by-step explanation:
Amount of bill = $75
Tip = 18%
Amount of tip = 
Amount of tip = 
Amount of tip = $13.50
Total bill = Bill + Tip
Total bill = 75 + 13.50
Total bill = $88.50