Answer:
1st answer
Step-by-step explanation:
Another way to say 2 coats is
to paint the fence twice
Also, that is the same as painting
2 identical fences
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Tom's rate is:
+1%2F8+ = ( 1 fence ) / ( 8 hrs )
Huck's rate is:
+1%2F5+ = ( 1 fence ) / ( 5 hrs )
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Let +t+ = the time in hrs for them
to paint 2 fences
+2%2Ft+ = ( 2 fences ) / ( t hrs )
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+1%2F8+%2B+1%2F5+=+2%2Ft+
Multiply both sides by +40t+
+5t+%2B+8t+=+80+
+13t+=+80+
+t+=+6.154+
It will take them 6.154 hrs
