With all GRE word problems, first ID the specific value being sought, in this case - how long ago was the fund half of the current value?

Then, begin reading the problem taking notes and doing obviously necessary calculations as you go. First we see that a fund was invested 25 years ago. This is currently irrelevant, so move on.

Next, we discover that the current fund value = $300,000.

Lastly, we are told that the value of the fund doubled each year for the last ten years. So, each prior year is = ½ the subsequent year.

Using this information we can find that the value of the fund in the year prior to the current is equal to $300,000 ÷ 2 = $150,000.

Remember the question asked how long ago was the fund half of its current value. $150,000 = ½ x 300,000 and was the value one year ago, so select the correct answer, choice B.