At $1$:$00$ P$.$M$.,$ oil begins leaking from a tank at a rate of $(3+0\mathrm{.}64$t$)$ gallons per hour. $($Round your answers to three decimal places.$)$

$($a$)$ How much oil is lost from $1$:$00$ P$.$M$.$ to $4$:$00$ P$.$M$.?$

gal

$($b$)$ How much oil is lost from $4$:$00$ P$.$M$.$ to $7$:$00$ P$.$M$.?$

gal