Answer:
Step-by-step explanation:
total weight is 4 tons.
ratio of weight of truck to weight of coal is 7:5....added = 12
so 7/12 of the total weight is the truck's
and 5/12 of the total weight is the coal
7/12 of 4 tons = 7/12 * 4 = 28/12 = 2 1/3 tons <== weight of truck
5/12 of 4 tons = 5/12 * 4 = 20/12 = 1 2/3 tons <== weight of coal
