Luna and Ginny each cast magic spells. The ratio of spells Luna casts to spells Ginny casts is represented in the tape diagram. Based on the ratio, what is the number of spells Ginny casts when Luna casts 20 spells?
Ratio luna 4 ginny 5

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.