Question 964077
Let {{{ p }}} = the original price/ kg
Let {{{ k }}} = the original gk purchased
(1) {{{ 500 = p*k }}}
(2) {{{ 500 = ( p + .25p )*( k - 5 ) }}}
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(2) {{{ 500 = 1.25p*( k - 5 ) }}}
and
(1) {{{ p = 500/k }}}
By substitution:
(2) {{{ 500 = 1.25*( 500/k )*( k - 5 ) }}}
(2) {{{ 500 = ( 625/k )*( k - 5 ) }}}
(2) {{{ 500 = 625 - 3125/k }}}
(2) {{{ 500k = 625k - 3125 }}}
(2) {{{ 125k = 3125 }}}
(2) {{{ k = 25 }}}
and
(1) {{{ p = 500/k }}}
(1) {{{ p = 500/25 }}}
(1) {{{ p = 20 }}}
the original price/kg was Rs 20
check:
(2) {{{ 500 = ( p + .25p )*( k - 5 ) }}}
(2) {{{ 500 = ( 20 + .25*20 )*( 25 - 5 ) }}}
(2) {{{ 500 = 25*20 }}}
(2) {{{ 500 = 500 }}}
OK