Question 945254
In {{{ 3*5 = 15 }}} days, they will clean their rooms 
on the same day, so
{{{ 1 + 15 = 16 }}}
This is april 16
{{{ 1 + 7 = 8 }}} is the next saturday
{{{ 8 + 7 = 15 }}} is the saturday after that
April 16 is a sunday