d1 + d2 = 300m,

0.5gt^2 + (75t + 0.5gt^2) = 300m,

Since g in the 1st term is positive and

g in the 3rd is negative, they cancel

each other and the Eq becomes:

75t = 300,

t = 4 seconds.

d1 = 0.5*9.8*4^2 = 78.4m. below top

of tower = 300 - 78.4 = 222m above

ground.

d2 = 75*4 - 0.5*9.8*4^2,

d2 = 300 - 78.4 = 222m above ground.

Therefore, the 2 stones meet 4s after

release at a distance of 222m above

ground.