At 2: 00 pm there are 350 freshmen and 200 sophomores at a school carnival. after 2: 00 pm 20 freshman leave every hour and 35 sophomores arrive every half hour.

what is the ratio of freshman to sophomores at 4: 00 pm in fraction form

160:340

Step-by-step explanation:

The hours between 2:00pm and 4:00pm is 2 hours. If originally 350 freshman and 200 sophomores are at the carnival, and 20 freshman leave every hour, we can determine how many freshman left in 2 hours:

and if 35 sophomores arrive every half our, we know that for every two hours there is 4 half hours, therefore:

The amount of freshman at 4:00pm:

and the amount of sophomores:

the ratio is 160:340