a very fast way to do it:
Trivially 8.8*5>10, so the power of 10 is 6+2+1 = 9.
Therefore, the answer is 
Each dvd cost $7.50 how? Your friends buy 8 dvd's and in total is 60, you want to divide 60 from 8 and find that it's 7.50 and then multiply 8 to 7.50 and it should be 60. Hope this helps!!
Answer:
72
Step-by-step explanation:
156 divided by 13 times 6.