Step-by-step explanation: Isolate the variable by dividing each side by factors that don't contain the variable.
Answer: The total cost is
assuming the cost for 1 adult is
and the cost for 1 child is 
Step-by-step explanation:
Assuming the cost for 1 adult is
and the cost for 1 child is
:
and 
Then the expression that gives the total cost
is solved as:

Answer:
1000 is the best answer yet
Answer:
80
Step-by-step explanation:
50 problems/x total = 62.5%
50/62.5=0.8 problem for each percent
0.8 * 100 percent = 80 problems