I’m pretty sure it is (7, 2)
So to set up the equation we have:
<span><span><span>4M</span><span>4+M</span></span>=<span>127</span></span>
<span>28M=12(4+M)</span>
<span>28M=48+12M</span>
<span>28K−12M=48</span>
<span>(28−12)M=48</span>
<span>16K=48</span>
<span>M=<span>4816</span></span>
<span>M=3</span>
So Marna can clean the chimney alone in 3 hours
Please include the diagram
