Because x was *3 you had to y*3 which is
y=6
If h is m above the ocean and your trying to find when the rocket reaches that ocean… as the function gives the height above the ocean at a given time, when the height equals 0 the rocket will have reached the ocean so solve for t when h=0. working out in the photo. i got t=48.88seconds
245 x 0.45 = 110.25
110.25 is your answer
hope this helps