Nyla

07-18-2013, 02:56 PM

SAT math average statistics

Could you help with the following question:

"The average of x and y is 10 and the average of x,y and z is 15. Find the value of z."

Thanks in advance!!:):)

Could you help with the following question:

"The average of x and y is 10 and the average of x,y and z is 15. Find the value of z."

Thanks in advance!!:):)