A grain depot originally stores a batch of grain. After two fifths of it is transported away, it carries in 5.5 tons of grain. This means that the amount of grain to be stored is just 80% of the original amount of grain. How many tons of grain to be stored in the depot?

A grain depot originally stores a batch of grain. After two fifths of it is transported away, it carries in 5.5 tons of grain. This means that the amount of grain to be stored is just 80% of the original amount of grain. How many tons of grain to be stored in the depot?

5 / [(80% - (2 / 1-5)] = 27.5 tons