This is how I would solve it, I would act as if there were 36 people in the class. 36÷6=6×5=30 30÷3=10×2=20 20/36=10/18=5/9 You could also try another number such as 24; 24×(5÷6)=20 20×(2/3)=13.3(3 repeating) 13.333/24=5/9 5/9 people have dogs. Tell me if this helps.