Roberto skips 70 times per minute because 4,200 / 60 = <<4200/60=70>>70.

Together they skip 150 times a minute.

They will skip 2,250 times because 150 x 15 = <<150*15=2250>>2,250

# Answer

2,250
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Roberto and Valerie are jumping rope at recess. Roberto can skip 4,200 times an hour. Valerie can skip 80 times a minute. If they jump rope for fifteen minutes straight, how many skips will they total?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
2,250
Roberto and Valerie are jumping rope at recess. Roberto can skip 4,200 times an hour. Valerie can skip 80 times a minute. If they jump rope for fifteen minutes straight, how many skips will they total?
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