Question 697782
Let {{{ b }}} = number of bicycles
Let {{{ t }}} = number of tricycles
Both types have 1 seat each, so
(1) {{{ b + t = 24 }}}
and
(2) {{{ 2b + 3t = 61 }}}
-------------------
Multiply both sides of (1) by {{{ 2 }}}
and subtract (1) from (2)
(2) {{{ 2b + 3t = 61 }}}
(1) {{{ -2b - 2t = -48 }}}
{{{ t = 13 }}}
and
(1) {{{ b + t = 24 }}}
(1) {{{ b + 13 = 24 }}}
(1) {{{ b = 11 }}}
There are 11 bicycles and 13 tricycles
check answer:
(2) {{{ 2b + 3t = 61 }}}
(2) {{{ 2*11 + 3*13 = 61 }}}
(2) {{{ 22 + 39 = 61 }}}
(2) {{{ 61 = 61 }}}
OK