Given that cost of 1 concert ticket = $7.50
Given that "a local business agrees to donate an additional $0.50 for each $1.00 in tickets sales to the band for their trip."
Donation $0.50 is half of $1. So that means you are getting half of the ticket price as donation
half of $7.50 is $3.75
So the effective collection per ticket = original cost + donation = $7.50 + $3.75 = $11.25
Money needed for trip is not given so let it be x.
Now the least number of tickets that needs to be sold is given by x/11.25
