Question #254f8

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Answer 1 · 2017-10-07T03:35:05

28 laps

Let Jackie's laps = J, and Ronnie's = R.

Now turn the info you're given into equations:

#2J = 3R# (for every three laps of J, R swims 2)

#J+R=70# (total laps = 70)
#R=70-J# (rearranging)

#2J=3(70-J)# (getting rid of a variable - plugging in what R's equal to)

#2J=210-3J#
#5J=210#
#J=42#

Now put this back into the first equation to find #R#:
#42+R=70#
#:. R=28#

So Ronnie swam 28 laps.