What will the price be if they buy 30? Which is the flight for Chicago?

M: They are exactly what we need. The only problem is the price.
W: How much do they cost?
M: $60.
W: If we buy 30, what discount will they give us?
M: 10%.
W: What if we bought 100?
M: We’d get a higher discount, but we’d never be able to sell them all.

W: Would all passengers for flight LH4521 to Brisbane please go to gate number 40; Flight LH4155 to Chicago, is now also boarding at gate number 42.