Qames can eat 25 marshmallows is 20 minutes. Dylan can eat 25 in one hour. In how much time will the two eat 150 marshmallows?
Choose the correct choice from the following options:
A) 40 minutes . B) 1 hour and 30 minutes . C) 1 hour . D) 1 hour and 40 minutes . E) 2 hours and 15 minutes .

Rationale: rate = output / time qames rate = 25 / 20 = 5 / 4 dylan rate = 25 / 60 = 5 / 12 combined rate = 5 / 4 + 5 / 12 = 20 / 12 combinedrate * combinedtime = combinedoutput 20 / 12 * t = 150 t = 90 mins = > 1 hr 30 min
Answer: C