What is the angle in a circle, given an arc of 160 degrees?

Which is equivalent to 10/12? options: 10/18 5/6 3/12 9/11

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?

Having a hard time understanding this question (see attachment).