1.  By which number, the trained unmarried nurses in the hospital are represented ?

A. 6
B. 5
C. 7
D. 4

Answer: Option D

Explanation:

This is because in the given data states that there are only married, trained nurses in the hospital. But in the question it is asked as whether the nurse is unmarried. Eventually, the answer should be the left out number (the number in the triangle&square). So the answer is 4 only.