B
You would divide 45 mm/15mm to get 3. Multiply 3 by 27 to get 81 mm.
The answer is c. hope that helped
1/3 of an hour is 20 minutes. If show 10 laps in 5 minutes, just divide 20 by 5, which gives you 4, then multiply 4 times 10. She can swim 40 laps in 1/3 of an hour. Hope that helps. Mark Brainliest if it does. Thank you!