One-tenth of the students at a nursery school are 4 years old or older. If 20 students have not yet reached their third birthday, and a total of 25 students are not between 3 years old and 4 years old, how many children are in the nursery school?	Pick one
A) 51  B) 20  C) 40  D) 50  E) 55
x/10 students are &gt; 4 yrs   20 students are &lt; 3 yrs   x/10+ 20 = 25   x/10 = 5   x = 50   Answer: 50
<result>D</result>
One-tenth of the students at a nursery school are 4 years old or older. If 20 students have not yet reached their third birthday, and a total of 25 students are not between 3 years old and 4 years old, how many children are in the nursery school?