Question 733736
Convert {{{ 7 }}} min to hrs:
{{{ 7/60 }}} hrs
Friend's head start is:
{{{ d[1] = 60*(7/60) }}}
{{{ d[1] = 7 }}} mi
Let {{{ t }}} = time in hrs for you to catch your friend
Let {{{ d }}} = distance in miles you have to go to catch friend
Friend's equation:
(1) {{{ d - 7 = 60t }}}
Your equation:
(2) {{{ d = 66t }}}
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Substitute (2) into (1)
(1) {{{ 66t - 7 = 60t }}}
(1) {{{ 6t = 7 }}}
(1) {{{ t = 7/6 }}} hrs
{{{ 7/6 = 1 + 1/6 }}}
{{{ (1/6)*60 = 10 }}}
It will take 1 hour and 10 min to catch friend
check:
(2) {{{ d = 66*(7/6) }}}
(2) {{{ d = 77 }}} mi
and
(1) {{{ d - 7 = 60*(7/6) }}}
(1) {{{ d = 7+ 70 }}}
(1) {{{ d = 77 }}}
OK