A three-tonne truck is allowed to have a gross mass (when fully loaded) of 7.5 tonnes. If it is carrying 0.5t of sand, 1.25t of brick and 4 bags of cement each weighing 40kg, what is the maximum extra mass which can still be placed on the truck before it is over-loaded?

My soliutions
0.5+1.25+(40x4)= 1.9
7.5 - 1.9= 5.6?

the correct answer is 2590kg or 2.59t

Please help!

Many thanks

40 kg = .04 tonnes

If the truck weighs 3 tonnes and it can only function up to 7.5 tonnes, then it can have a load of 4.5 tonnes.

4.5 - .5 - 1.5 - .04 = ?

I hope this helps.