Question 1154635
Home owner's rate of working:
[ 1 house roofed ] / [ 8 days ]
Professional's rate of working:
[ 1 house roofed ] / [ 5 days ]
let their rate working together be:
[ 1 house roofed ] / [ t days ]
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Add their rates to get rate working together
{{{ 1/8 + 1/5 = 1/t }}}
Multiply both sides by {{{ 40t }}}
{{{ 5t + 8t = 40 }}}
{{{ 13t = 40 }}}
{{{ t = 3.077 }}}
3.077 days
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check:
{{{ 1/8 + 1/5 = 1/t }}}
{{{ .125 + .2 = 1/3.077 }}}
{{{ .325 = .32499 }}}
The error is due to rounding off