Question 848358
Let {{{ a }}} = number of adults
Let {{{ g }}} = number of girls
{{{ g + 6 }}} = number of boys
{{{ a/g = 1/4 }}}
(1) {{{ g = 4a }}}
{{{ a/b = 1/5 }}}
{{{ b = 5a }}}
(2) {{{ g + 6 = 5a }}}
Substitute (1) into (2)
(2) {{{ 4a + 6 = 5a }}}
(2) {{{ a = 6 }}}
and
(1) {{{ g = 4a }}}
(1) {{{ g = 24 }}}
and
{{{ b = 5a }}}
{{{ b = 5*6 }}}
{{{ b = 30 }}}
The number of adults is 6
check:
a:g:b = 6:24:30
1:4:5 = 6:24:30
1:4:5 = 1:4:5
OK