Question 541310
Let {{{d}}}= number of quarters
Let {{{q}}} = number of quarters
given:
(1) {{{ q = 2d }}}
(2) {{{ 10d + 25q = 900 }}} ( in cents )
Substitute (1) into (2)
(2) {{{ 10d + 25*(2d) = 900 }}}
(2) {{{ 10d + 50d = 900 }}}
(2) {{{ 60d = 900 }}}
(2) {{{ d = 15 }}}
and, since
(1) {{{ q = 2d }}}
(1) {{{ q = 2*15 }}}
(1) {{{ q = 30 }}}
He has 15 dimes and 30 quarters
check:
(2) {{{ 10*15 + 25*30 = 900 }}}
(2) {{{ 150 + 750 = 900 }}}
(2) {{{ 900 = 900 }}}
OK