Which of the following promotions exemplifies the use of a fixed-ratio schedule of reinforcement? a café offers its customers a punch card. each time a patron purchases a beverage, a hole is punched; when ten holes are punched, the patron receives a free beverage. a café offers each patron an early morning two-for-one free-beverage-with-purchase deal from 5 to 6 a. m. on monday mornings. a café prints "you are a winner" on a random one-twelfth of its coffee lids; patrons receiving such a lid can redeem it for a free beverage. now and then, a café announces a two-for-one deal.

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.