Answer:
166 legos are required
Explanation:
In this case, let's analyze the data. We need 3 trophies, using at most 324 legos in total. The big trophy requires 220 legos, the smallest requires 135, so we need to know how much will be used in the medium trophy. This number should be 135 < X < 220
Now, if we know that the total legos to be used are 324, then, we can make a difference and sum for all the legos, and then, calculate the number of legos used.
Total legos = A + B + C
324 = 220 + 135 + C
324 = 355 + C
C = -31
This means that there is difference of 31 legos between the smallest and biggest trophy, therefore, this difference should be used and added to the smallest trophy and see how much Tristen use in the final trophy:
135 + 31
= 166 legos
So we need to use 166 legos to build the final trophy.