Answer
Find out the what is the number of weeks that have passed since since jeffrey had $250 .
To prove
Let us assume that the number of weeks be x .
As given
Jeffrey has $250 in the bank.
Each week he takes out $25.After a few weeks jeffrey has $87.50 left in the bank.
Than the equation becomes
87.50 = 250 - 25 x
87.50 = 250 - 25x
250 - 87.50 = 25x
162.5 = 25x
x = 6.5 weeks
Therefore it take 6.5 weeks (approx) that have passed since jeffrey had $250 .