The orange trees did not bear any fruit this year

(1) 300

Explanation

We will look for the key word is, of, and what number in the percent sentence and translate them to mathematical symbols to form a percent equation.  Then it will be clear what operation should be performed to find the unknown number.

First, translate to a percent equation

What number is 60% of 500?

x = 60% • 500

Now we perform the multiplication on the right side of the equation.

Write 60% as a decimal: 60% = 0.6

x = 0.6 • 500

Do the multiplication

x = 300

We have found that 300 is 60% of 500.  That is, 300 trees did not bear fruits this year.