John bought a bicycle for $20 sold it for $30 rebought it for $40 and resold it for $50. how much money did he make or loose?

There are several unique characteristics of qualitative research that make it distinct from quantitative research. describe the aspects of qualitative research and the elements of design that contribute to the rigor of the work. what actions of the researcher can compromise the integrity of the findings?

Prove that quadrilateral is a rhombus.

Could someone with number 1 and 2