1.

2.

3. -7/30
4. i believe it is the communitive of multiplication , but not 100% sure
I dont have the * exact answer * but i got 11 or 12. Hope this helps :))
For this case, the first thing we must do is calculate the total cost.
We have then:
C = (16) * (2.4) * (6)
C = 230.4 $
Then, the change it receives is given by:
250 - 230.4 = 19.6 $
Answer:
He has received 19.6 $ from $ 250