Respuesta :
Answer:
16 minute 30 seconds
Step-by-step explanation:
1 minute 30 seconds = 1.5 minutes
1.5 x 21 = 31.5 minutes
One person will make 10, one person makes 11.
11
11× 1.5 = 16.5
10× 1.5 = 15
16.5 is the answer
16.5 is the number that would be the correct answer to your question