Question 206442
This question basically says that (x+y+z)/3=80. That means the sum of the three numbers is 240, by cross multiplication. Given that two of the numbers are 74, and 78, and you know that the sum of all three is 240, we can subtract these values from 240 to obtain the value of our third number. So, the value of the third number is 240 - 74 - 78 = 88. 


Feel free to comment with any questions or concerns. -- David