Respuesta :

60 blocks in 30 min
18 blocks in 9 min
Method 1
60-18 = 42
42 blocks in 21 min
Method 2
30-9 =21 min

Answer:

Time taken by Susan to finish running is:

21 minutes

Step-by-step explanation:

Susan wants to run 60 blocks.

She has already run 18 blocks.

Blocks she has to run=60-18

                                    = 42

Susan can run 2 city blocks per minute.

i.e. Running 2 blocks takes time= 1 minute

So, Running 2×21 blocks takes time= 21 minutes

i.e. Running 42 blocks takes time= 21 minutes

Hence, Time taken by Susan to finish running is:

21 minutes