Respuesta :

9514 1404 393

Answer:

  10 minutes

Step-by-step explanation:

The current legal tender conversion rate is 50 kobo = 0.50 naira. Then the airtime balance is ...

  (300 NGN)/(0.50 NGN/s) × (1 min)/(60 s) = 300/(0.50×60) min = 10 min