A survey of 120 teachers determined the following:

70 had high blood pressure

40 had heart trouble

20 had both high blood pressure and heart trouble

What percent of the teachers surveyed had neither high blood pressure nor heart trouble?

Guest Jul 24, 2019

#1**+3 **

**A survey of 120 teachers determined the following:**

**70 had high blood pressure 40 had heart trouble 20 had both high blood pressure and heart trouble**

**What percent of the teachers surveyed had neither high blood pressure nor heart trouble?**

**Frist solution:**

\(\begin{array}{|l|c|c|c|} \hline & \text{blood} & \overline{\text{blood}} \\ & \text{pressure} & \overline{\text{pressure}} \\ \hline \text{heart} & \mathbf{20} & 40-20=20 & \mathbf{40} \\ \text{trouble} & & & \\ \hline \overline{\text{heart}} & & \color{red}x =50-20 = \mathbf{30} \\ \overline{\text{trouble}} & \\ \hline & \mathbf{70} & 120-70=50 & \mathbf{120} \\ \hline \end{array}\)

**Second solution:**

\(\begin{array}{|l|c|c|c|} \hline & \text{blood} & \overline{\text{blood}} \\ & \text{pressure} & \overline{\text{pressure}} \\ \hline \text{heart} & \mathbf{20} & & \mathbf{40} \\ \text{trouble} & & & \\ \hline \overline{\text{heart}} & 70-20=50 & \color{red}x = 80-50 =30 & 120-40 = 80 \\ \overline{\text{trouble}} & \\ \hline & \mathbf{70} & & \mathbf{120} \\ \hline \end{array}\)

heureka Jul 24, 2019