How do you figure this out? The answer is 50,000?

Question

Q. Of the 30,000 calories of potential energy fixed during photosynthesis by corn, wheat, and barley, the efficiency of energy harvest was 60%. Using the equation (Efficiency=Output/Input X 100), the original number of calories absorbed from the sun was...?

The Trophic pyramid states Corn, Wheat, and Barley produced 500.0

Answer 1

30,000/60%

=30,000/0.60

=50,000

Answer 2

Output = 30 000 calories

Efficiency = 60%

60% = 30 000 calories/Input (x 100%)

(by the way it's 100%, not 100)

Input = 30 000 calories/0.60

Input = 50 000 calories.