Question 1050086
Average speed is always:
[ total distance traveled ] / [ total time spent traveling ]
Let {{{ d }}} = one-way distance between home and shop
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Time spent jogging:
{{{ t[1] = d / 12 }}} hrs
Time spent walking:
{{{ t[2] = d / 4 }}} hrs
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Average speed =
{{{ (2d) / (( t[1] + t[2] )) }}}
{{{ (2d) / (( d/12 + d/4 )) }}}
{{{ ( d/d )*( 2 / ( 1/12 + 1/4 )) }}}
{{{ 2 / (( 1/12 + 3/12 )) }}}
{{{ 2 / ( 4/12 ) }}}
{{{ 2 / ( 1/3 ) = 6 }}}
The average speed is 6 km/hr