Departments A $,$ ?B $,$ ?C $,$ ?and D need to be assigned to four rooms $1,2,3,$ ?and $4.$ ?These rooms are arranged in a row, in that order, with $20$ ?meters between each. The departmental work flows are contained in the table below.

?

What is the material handling total of assigning A $-1,$ ?B $-2,$ ?C $-3,$ ?D $-4?($ The answer should be a whole number $)$

?

?

Flow Matrix

?

?

Dept. A

?

Dept. B

?

Dept. C

?

Dept. D

Dept. A

?

$0$

?

$30$

?

$50$

?

$20$

Dept. B

?

$5$

?

$0$

?

$40$

?

$20$

Dept. C

?

$0$

?

$10$

?

$0$

?

$40$

Dept. D

?

$10$

?

$25$

?

$0$

?

$0$