Adults and children can sign up for a virtual fun run race. It costs $30 per adult and $20 per child for the fun run race. The expression 30a + 20c can be used to calculate the cost (in dollars) for adults and c children to participate in the virtual fun run. Use the expression to determine the total cost (in dollars) for 2 adults and 4 children to participate in the fun run.

Kevin has a spinner that has 10 equal sections and 2 sections of each color—red, blue, green, yellow, and purple. kevin spins the spinner 180 times. kevin determines about how many times the spinner will land on red or green, and his work is shown below. -kevin has the formula reversed; it should be the total number of sections over the number of red or green sections. -kevin should have used a 4 in the numerator because there are 2 red sections and 2 green sections. -kevin should multiply by the number of sections in the spinner rather than the total number of spins. -kevin calculated the prediction correctly and did not make any mistakes.