Answer:
no
Explanation:
The amount of sand left in the truck after t minutes is ...
remaining = 4 -(3/8)/(2 7/10)t
That is, the rate at which the amount is decreasing is 3/8 ton per 2 7/10 minutes, or ...
(3/8)/(2 7/10) = (15/40)/(108/40) = 15/108 = 5/36 . . . tons per minute
The time required for the remaining amount to be zero is ...
remaining = 0 = 4 -5/36t
t = 4(36/5) = 28.8 . . . minutes
There will not be any sand left after 30 minutes. It will have run out after 28.8 minutes.