Question 879122
Let {{{ s }}} = your speed to arrive on time in km/hr
Let {{{ t }}} = your elapsed time to arrive on time in hrs
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(1) {{{ 180 = s*t }}}
(2) {{{ 180 = 45*( t + 1/4 ) }}} ( note that 15 min = 1/4 hr )
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(2) {{{ 180 = 45t + 45/4 }}}
(2) {{{ 720 = 180t + 45 }}}
(2) {{{ 180t = 675 }}}
(2) {{{ t = 3.75 }}}
and
(1) {{{ 180 = s*3.75 }}}
(1) {{{ s = 180/3.75 }}}
(1) {{{ s = 48 }}}
My answer is (D), 48 km/hr