Let the age of three children be x,y and z.

And relation between the ages is x+y+z = 1440 minutes and x*y*z = 86400 seconds.

Now there might be multiple answers to this question. But one possible way to solve this is calculated below :

Let the age of three children be same, x = y = z.
So, x*y*z = 86400 seconds

x^3 = 86400 seconds

x = 28800 seconds

x = 28800/60 minutes

x = 480 minutes.

So the age of the children is 480 minutes or 28800 seconds each.