Question: 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 ?
A) 51
B) 20
C) 40
D) 50
E) 55
Correct answer: D
Grade: 7 | Topic: Expressions and Equations | Difficulty: Hard | Standard: 7.EE.B.3