Y YOUWANTME New member Nov 7, 2011 #1 Working alone, it takes Joe 11 hours to tar a roof. Mark can tar the same roof in 12 hours. If they worked together how long would it take them? I need to know how to do it so can you explain or point me to a helpful site?
Working alone, it takes Joe 11 hours to tar a roof. Mark can tar the same roof in 12 hours. If they worked together how long would it take them? I need to know how to do it so can you explain or point me to a helpful site?
I I'mwithStupid New member Nov 9, 2011 #2 Joe tars at the rate of 1/11 roofs per hour Mark tars at the rate of 1/12 roofs per hour so together they tar at (1/11 + 1/12) roofs per hour or, simplified: 23/132 roofs per hour. so it would take them: 132/23 hours per roof or about 5.74 hours ??
Joe tars at the rate of 1/11 roofs per hour Mark tars at the rate of 1/12 roofs per hour so together they tar at (1/11 + 1/12) roofs per hour or, simplified: 23/132 roofs per hour. so it would take them: 132/23 hours per roof or about 5.74 hours ??