Solve this please do the model

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?

Sketch the vector field vector f( vector r ) = 8vector r in the xy-plane. select all that apply. the length of each vector is 8. the lengths of the vectors decrease as you move away from the origin. all the vectors point away from the origin. all the vectors point in the same direction. all the vectors point towards the origin. the lengths of the vectors increase as you move away from the origin.

Which expressions equal 9 when x=4 and y=1/3 a. x2+6y b. 2x + 3y c. y2-21x d. 5 (x/2) -3y e. 3x-9y