Encountered this question of the LEED NC exam, and still cannot figure out the answer.

A womans bathroom has one dual flush toilet, and two low flow toilets. what is the daily usage per woman?

a. 1 dual flush, 2 low flow. 3 lavatories

b. 2 dual flush, 2 low flow, 4 lavatories

c.d. etc, etc. (just a different combination of numbers)

Any help??

Do you calculate a dual flush twice??