Kelyse's preschool tuition is $180 per week. She receives a small discount for honor roll, $50 per month. Her grandparents help out and pays 20% of her tuition. How much do her grandparents pay?

Campus rentals rents 2 and 3 bedrooms apartments for $700 ans $900 a month respectively. last month they had six vacant apartments and reported $4600 in lost rent. how many of each type of apartment were vacant?