Brandon has a big night planned but must first take care of his laundry. He has sorted items into seven different types and determined the time each load will spend first in the washing machine and then in the dryer.

Type

Washer

Dryer

Whites

$45$

$40$

Permanent press

$30$

$35$

Leathers

$15$

$10$

Silk

$25$

$20$

Cotton

$30$

$25$

Towels

$40$

$60$

Heavily soiled

$90$

$45$

$$

What is the minimum makespan possible?

a$.$

$310$ minutes

b$.$

$300$ minutes

c$.$

$290$ minutes

d$.$

$280$ minutes