Official Solution:In a graduating class of 232 students, 144 took geometry and 119 took biology. What is the difference between the greatest possible number and the smallest possible number of students that could have taken both geometry and biology?A. 144
B. 119
C. 113
D. 88
E. 31
First of all, notice that since 144 took geometry and 119 took biology, the number of students who took both geometry and biology cannot be greater than 119.
Therefore, the
greatest possible number of students that could have taken both geometry and biology, is 119.
Next:
{Total} = {geometry} + {biology} - {both} + {neither};
232 = 144 + 119 - {both} + {neither};
{both} = 31 + {neither}.
{both} is minimized when {neither} is 0. In this case {both} = 31.
Therefore, the
smallest possible number of students that could have taken both geometry and biology, is 31.
Thus, the answer is 119 - 31 = 88.
Answer: D