A train traveling at a speed of 20mph departs from Manhattan and heads towards New Jersey. At the same time, a train heading to Manhattan from New Jersey is departing at the same time, and will be going 40mph. If the two places are 120 miles apart, how far from New Jersey will the trains meet?
E. 40 miles F. 60 miles G. 80 miles H. 100 miles

PLS ANSWER WITH THE WORK..... THE ANSWER IN THE ANSWER SHEET IS G 80 MILES BUT I NEED THE WORK ON HOW TO GET TO TE ANSWER.