Question 474238
Let {{{t}}} = time to mow 1 lawn working together
Add their rates of working
Jack's rate:
1 lawn mowed / 5 hours
Marilyn's rate:
1 lawn mowed / 3 hours
Rate working together = {{{ 1/5 + 1/3 }}}
Rate working together = {{{ 3/15 + 5/15 = 8/15 }}}
{{{ 8/15 = 1/t }}}
{{{ t = 15/8 }}}
{{{ t = 1.875 }}} hrs
Time  - 1 hr + {{{ .875*60 = 52.5 }}} min
It takes them 1 hr and 52.5 min working together