Respuesta :

Steven92
Well Susan has run 18 blocks

So every 2 blocks is 1 minute

2 x 9 = 18 so far 9 minutes

Now the remainder is 42 blocks

20 blocks is 10 minutes

20 x 2 = 40 blocks in 20 minutes

Then the last 2 blocks is 1 minute so

20 + 1 = 21 minutes