6 neighbors share 4 pies equally. How much pie does each neighbor get

Which ordered pair (c,d) is a solution to the given system of linear equations- c+2d=13 -9c-4d=-15

Some boys and girls were asked if they had a pet. one third of the group were boys. there were 20 boys. 20% of the girls had a pet. boys with a pet : girls with a pet = 1 : 5 i need to know how many girls there are.

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?