Answer:
250 shirts
Step-by-step explanation:
Let x be the number of t-shirts that were brought to the show.
They did not sell 10% of the shirts; 10% = 10/11 = 0.10; this gives us the expression 0.10x to represent the unsold shirts.
We know they had 25 shirts left; this gives us the equation
0.10x = 25
To solve, divide both sides by 0.10:
0.10x/0.10 = 25/0.10
x = 250