How is this wrong? I'm confused

Answer:
60m = t
Step-by-step explanation:
For " per minute ( 1 minute ) ", he can type 60 words.
For " m minutes ", he can type
m times 60
= m x 60
= 60m
Hence,
60m = t
Answer:
The answer would be B
Step-by-step explanation:
Since Miles can write 60 words PER minute. Per is a key work for multiplication. So it would be 60m = t instead of m/60 = t.