Of 60 children, 30 are happy, 10 are sad, and 20 are neither happy nor sad. There are 17 boys and 43 girls. If there are 6 happy boys and 4 sad girls, how many boys are neither happy nor sad?
Choose the correct choice:
A) 5	B) 4	C) 6	D) 8	E) 10
Venn diagrams are useful for multiple values of a single variable e.g. State of mind - happy/sad/neither. When you have two or more variables such as here where you have gender - boy/girl too, it becomes unwieldy. In this case, either use the table or logic.   Table method is shown above; here is how you will use logic:   There are 6 happy boys.   There are 4 sad girls but total 10 sad children. So rest 6 sad children must be sad boys.   We have 6 happy boys and 6 sad boys. Total we have 17 boys. So  17 - 6 - 6= 
<gadget id="calculator"> 17 - 6 - 6</gadget>
<output>5</output>
5 boys must be neither happy nor sad.   5nswer (5)
<result>A</result>
Of 60 children, 30 are happy, 10 are sad, and 20 are neither happy nor sad. There are 17 boys and 43 girls. If there are 6 happy boys and 4 sad girls, how many boys are neither happy nor sad?