Quote:
Originally Posted by BFT3K
Bill can mow the lawn in 6 minutes. His brother Jim can mow it in 9 minutes. How long will it take them to do it together, if each has his own lawnmower?
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bill. 1lawn = 6mins
jim. 1lawn = 9mins
bill 1/6(.16 or 16%) of lawn in 1min
jim 1/9(.11 or 11%) of lawn in 1min
add that together to find out how much of the lawn they both did in 1min.
.27 or 27.6% in 1min.
100/27.6 x 1min = 3.62min. (3mins 37 secs)