I don't understand

Question

The city calculates that it takes a garbage truck 12 and 1 over 2. minutes to clear trash on one city block. On Tuesday four garbage trucks are collecting trash on 56 city blocks.

How many minutes will it take the trucks to clear the trash if each truck collects garbage at the same rate?

Answer 1

56 blocks are shared by 4 trucks 

 

So each truck gets a share of 56 /4 = 14 blocks

 

One block takes  12 and 1 over 2 = 25/2 min = 12.5 min

so 14 blocks will take 12.5 x 14 = 175 min

so in 175 min all blocks get cleared of garbage

Assuming all trucks are working together at the same time