#### Answer

The unnecessary information in the problem is the weight of the tires.
Amount left = 72.

#### Work Step by Step

Total amount before spending = 250
No. of tires to be purchased = 4
Cost of each tire including tax = 42 + 2.50 = 44.50
So, to find out money left after buying four tires, we don't need the information about the weight of each tire.
amount spent in buying 4 tires = 4 x 44.50 = 178
Amount left = 250 - 178 = 72