During a school lunch, the cafeteria sold two-fifths as many white milks as chocolate milks. if there were 35 milks sold, how many chocolate milks were sold?

C + w = 35

w = 2/5c

c + 2/5c = 35

5/5c + 2/5c = 35

7/5c = 35

c = 35 / (7/5)

c = 35 * 5/7

c = 175/7

c = 25 < = = = there were 25 chocolate milks sold

c + w = 35

25 + w = 35

w = 35 - 25

w = 10 ... there were 10 white milks sold