A hot-air balloon 70 meters above the ground is falling at a constant rate of 6 
meters per second while another hot-air balloon 10 meters above the ground is 
rising at a constant rate of 15 meters per second. To the nearest tenth of a second, 
after how many seconds will the 2 balloons be the same height above the 
ground? 
A. 8.9 
B. 6.7 
C. 2.9 
D. 0.4 
E. 0.2