The formula for the speed is
Where S is the speed, d is the distance travelled, and t is the time taken
On rearranging it,
In the question, the speed is given in the unit m/s. And the distance is given in km. Before solving we have to change the units of all the quantities to SI units
Therefore,
On substituting all the known values into the equation,
Therefore the bouquet remained in the air for 153.85 s.