Of the 720 students at a certain university, 25 percent are seniors. If x seniors were to graduate early and leave the university and no additional students entered or left the university, what value of x would reduce the number of seniors at the university to 20 percent? Choose the correct option.
A) 30	B) 36	C) 42	D) 45	E) 48
Sol:   180-x= 20% of (720-x)   4x=180   x=45   ANSWER:45
<result>D</result>
Of the 720 students at a certain university, 25 percent are seniors. If x seniors were to graduate early and leave the university and no additional students entered or left the university, what value of x would reduce the number of seniors at the university to 20 percent?