Train X and train Y pass one another traveling in opposite directions. Twelve minutes later they are 100 miles apart. If train X’s constant speed is 30 miles per hour greater than train Y’s, how far does train X travel during that time?
Choose the most appropriate option.
A) 28  B) 40  C) 53  D) 72  E) 80
Let the rate of the Train Y be R   Then the rate of the Train X will be R+30 (given)   As per relative rate concept, the rate at which they are increasing the distance between them is R+(R+30) [add the rates] i.e. 2R+30   d=100 and t = 12 min i.e 12/60 hr   using RTD table, (2R+30) * 12/60 = 100 ==&gt; R= 235 miles/hr   So the rate of train X is 265 miles/hr (since R+30)   The distance traveled by Train X in 12 min is R*T = 265 * 12/60= 
<gadget id="calculator">265 * 12/60</gadget>
<output>53</output>
53 miles (53)
<result>C</result>
Train X and train Y pass one another traveling in opposite directions. Twelve minutes later they are 100 miles apart. If train X’s constant speed is 30 miles per hour greater than train Y’s, how far does train X travel during that time?