f VLC $=$ $$1,600,$ price is $$20$ per item, contribution margin $=20\%,$ and the repurchasing frequency is

once every six years, $($a$)$ what is the defection rate, and $($b$)$ what is the retention rate?

$9.$ If VLC $=$ $$3,600,$ price is $$50$ per item, contribution margin $=32\%,$ and the repurchasing frequency is

once every five years, $($a$)$ what is the defection rate, and $($b$)$ what is the retention rate?

$10.$ If VLC $=$ $$50,000,$ price is $$120$ per item, contribution margin $=16\%,$ and the repurchasing frequency

is $52$ times per year, $($a$)$ what is the defection rate, and $($b$)$ what is the retention rate?