Question 1070841
Let {{{ r }}} = rate of interest for 1st CD
Let {{{ P }}} = the principal for both CDs
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(1) {{{ r*P = 270 }}}
(2) {{{ ( r + .04 )*P = 450 }}}
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(1) {{{ P = 270/r }}}
(2) {{{ ( r + .04 )*( 270/r ) = 450 }}}
(2) {{{ 270 + 10.8/r = 450 }}}
(2) {{{ 10.8/r = 180 }}}
(2) {{{ 180r = 10.8 }}}
(2) {{{ r = .06 }}}
and
{{{ r + .04 = .1 }}}
The rate of interest for 1st CD is 6%
The rate of interest for 2nd CD is 10%
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check:
(1) {{{ r*P = 270 }}}
(1) {{{ P = 270/r }}}
(1) {{{ P = 270/.06 }}}
(1) {{{ P = 4500 }}}
and
(2) {{{ ( r + .04 )*P = 450 }}}
(2) {{{ ( .06 + .04 )*P = 450 }}}
(2) {{{ .1P = 450 }}}
(2) {{{ P = 4500 }}}
OK