To find the maximum number of tacos a customer can order with $100, we need to determine the cost per taco.
From the given sequence:
- The cost for 1 taco is $3.75.
- The cost for 2 tacos is $7.50.
- The cost for 3 tacos is $11.25.
Each taco costs $3.75.
Now, we can calculate how many tacos can be bought with $100 by dividing the total amount by the cost of one taco:
\[ \text{Number of tacos} = \frac{100}{3.75} \]
Calculating that:
\[ \frac{100}{3.75} = \frac{100 \times 100}{375} = \frac{10000}{375} \approx 26.67 \]
Since we cannot order a fraction of a taco, we round down to the nearest whole number.
Thus, the maximum number of tacos that can be ordered is 26.
So the answer is 26 tacos.