Respuesta :
Answer:
b
Step-by-step explanation:
convert 2 1/2 hours into minutes to be easier to work with
15 / 150 = 10 minutes
every 10 minutes he pots a plan.
there are 210 minutes in 3 1/2 hours
210 / 10 = 21
The answer is B because he plants one each 10 minutes and there is 210 minutes in 3 1/2 hours 210/10=21