What is the arrangement of genes on chromosomes resulting from crossing over called?

There are three genes $a, b,$ and $c$. The recombination frequency between $a$ and $b$ is $20\%$,between $b$ and $c$ is $28\%$,and between $a$ and $c$ is $8\%$. What is the possible arrangement of these genes on the chromosome?

The recombination frequency between genes $B$ and $A$ is $5\%$. The recombination frequency between genes $A$ and $C$ is $15\%$. What is the possible sequence of these genes on the chromosome?

Crossing over is

Geneticists plot the relative locations of genes on chromosomes by which of these methods?

The map distance between genes $A$ and $B$ is $3$ units,between $B$ and $C$ $10$ units,and between $C$ and $A$ $7$ units. The order of the genes in a linkage map constructed on the above data would be: