Mm myes pet phrog

There were 25 students who answered to a survey about sports. four-fifths of them like football. how many students like football?

Ineed with question three. i don't understand how i'm supposed to achieve 3 marks.

Cate purchases $1600 worth of stock and her broker estimates it will increase in value by 4.2% each year. after about how many years will the value of cate's stock be about $2000