city a and city b are 140 miles apart. train c departs city a, heading towards city b, at 4: 00 and travels at 40 miles per hour. train d departs city b, heading towards city a, at 4: 40 and travels at 20 miles per hour. the trains travel on parallel tracks. at what time do the two trains meet? Options.
A) 5 : 00 B) 5 : 30 C) 6 : 40 D) 6 : 30 E) 7 : 00
<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<gadget id="calculator">6 / 40</gadget>
<output>3/20 = around 0.15</output>

<result>C</result>
city a and city b are 140 miles apart. train c departs city a, heading towards city b, at 4: 00 and travels at 40 miles per hour. train d departs city b, heading towards city a, at 4: 40 and travels at 20 miles per hour. the trains travel on parallel tracks. at what time do the two trains meet?
divide(add(4, const_2), 40)
"train c has traveled 20 mi in the half hour before train d has started its journey . 140 - 20 = 120 40 + 20 = 60 mph 120 mi / 60 mph = 2 hrs 4 : 40 pm + 2 hrs = 6 : 40 pm answer : c . 6 : 40"