What will be the number of linkage groups in maize if it has $10$ pairs of chromosomes?

Morgan and his group observed that when genes are grouped on the same chromosome,some genes are very tightly linked and show:

Choose the incorrect statement.

There are three genes $a, b, c$. The percentage of crossing over between $a$ and $b$ is $20\%$,between $b$ and $c$ is $28\%$,and between $a$ and $c$ is $8\%$. What is the sequence of genes on the chromosome?

When white-eyed and miniature-winged $Drosophila$ $melanogaster$ is crossed with its wild type,it produces which of the following percentages of recombinants (in $\%$)?

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?