The profit Ronald wants is $3000 / 3 = $<<3000/3=1000>>1000

The profit per phone sold will be $1000 / 200 phones = $<<1000/200=5>>5/phone

The cost of each phone is $3000 / 200 phones = $<<3000/200=15>>15/phone

The selling price including the profit will be $15/phone + $5/phone = $<<15+5=20>>20

# Answer

20
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Ronald wants to make profits by re-selling some phones he bought a week ago. He bought 200 units for just $3000, and he wants to gain a third of the initial investment in profits when all units are sold. Including the profit margin, what will be the selling price for each phone?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
20
Ronald wants to make profits by re-selling some phones he bought a week ago. He bought 200 units for just $3000, and he wants to gain a third of the initial investment in profits when all units are sold. Including the profit margin, what will be the selling price for each phone?
train