What is the answer to thisss ?

64 minutes to put as many boxes as possible.
Explanation: The dimensions of Ellie's boxes in meters are: 0.45m by 0.40m by 0.35 ( to convert from centimeters to meters we just divide by 100, because 1m =100cm). therefore the volume of each box is 0.063 m3
Now the dimensions of the empty van are 3.6m by 1.6m by 2.1 m, therefore its volume is: 12.096 m3

So the amount of boxes that Ellie can put in the van is equal to the volume of the van divided by the volume of each box: 192 boxes

So 192 boxes can be put into the van.
Now Ellie can put 3 boxes in the van in 1 minute, therefore the amount of time it will take her to put 192 boxes into the van will be: 64 minutes

So it takes Ellie 64 minutes to put as many boxes into the van as she can.