Question 653705
Add their rates of filling to get the rate
for them filling together
Since you are only dealing with 400 bottles
call that 1 job
( 1 job / 1 hr ) + ( 1 job ) / ( 1.5 hr ) = 1 job / x hrs
{{{ 1/1 + 1/1.5 = 1/x }}}
Multiply both sides by {{{ 1.5x }}}
{{{ 1.5x + x = 1.5 }}}
{{{ 2.5x = 1.5 }}}
{{{ x = 15/25 }}}
{{{ x = 3/5 }}}
{{{ (3/5)*60 = 36 }}}
With both machines working it takes 36 minutes to fill 400 bottles