It could still carry 147 boxes of milk. Knowing that 60 is 1/3 of 180 cavans of rice, the truck will be filled with an additional 2/3 of either 180 cavans of rice (which is 120) or 220 boxes of milk(which is 146.67 or 147). Since it demands milk, we take the 2/3 of 220 boxes of milk, which is 146.67 or 147. The solution is a proportion.. "(180/120) = (220/x)" where x is 147. Hope you've understood