The slope of the line joining the point (2,2p) and (4,1) is -3/2. Then p=………. A.2 B.-2 C.1/2 D.-1/2 E.2/3 If the points (1,1),(3,2) and (9,k) are on the same straight line , then k=…….. A.4 B.5 C.6 D.7