Question 1060817
A train travels 25 km/h faster than a bus. The train takes 3 hours less then the bus to travel 1500 km. How long will it take for the train to travel the 1500 km?
<pre>Let time train takes to travel 1,500 miles be T
Then time bus takes is: T + 3
Speed of train = {{{"1,500"/T}}}, and speed of bus = {{{"1,500"/(T + 3)}}}
We then get the following SPEED equation: {{{matrix(1,3, "1,500"/T, "=", "1,500"/(T + 3) + 25)}}}
1,500(T + 3) = 1,500T + 25T(T + 3) ------ Multiplying by LCD, T(T + 3) 
{{{1500T + 4500 = 1500T + 25T^2 + 75T}}}
{{{25T^2 + 1500T + 75T - 1500T - 4500 = 0}}}
{{{25T^2 + 75T - "4,500" = 0}}}
{{{25(T^2 + 3T - 180) = 25(0)}}}
{{{T^2 + 3T - 180 = 0}}}
(T - 12)(T + 15) = 0 
T, or time train takes = {{{highlight_green(matrix(1,2, 12, hours))}}}        OR         T = - 15 (ignore)