Question 401527
Let {{{t}}} = time for both
Let {{{v}}} = velocity of car
Given:
for car:
(1) {{{75 = v*t}}}
for moped
(2) {{{25 = (v - 40)*t}}}
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From (1):
{{{t = 75/v}}} 
(2) {{{25 = (v - 40)*(75/v)}}}
{{{25 = 75 - 3000/v}}}
{{{25v = 75v - 3000}}}
{{{50v = 3000}}}
{{{v = 60}}}
{{{v - 40 = 20}}}
The car's rate is 60 mi/hr
The moped's rat is 20 mi/hr