Answer: Cole saw a lower ratio of blue to red cars in May.
Step-by-step explanation:
Cole got a job selling cars in May, he sold three red cars and four blue cars. This means that the ratio of blue cars to red cars in may is
3/4 = 0.75 : 1
in June, he sold two red cars and five blue cars. This means that the ratio of blue cars to red cars in June is
5/2 = 2.5 : 1
Since 0.75 is lower than 2.5, it means that the month in which Cole saw a lower ratio of blue to red cars is May.