<PRE><B>Question 1101006</B>
The average temperature of the first three days of a week is 27 degrees
 and of the next three days is 29degrees .
If the average of whole of the week is 28.5 degree the temperature of the last day of the week is?
:
let s = last day average temp
:
{{{(3(27) + 3(29) + s)/7}}} = 28.5
81 + 87 + s = 7(28.5)
168 + s = 199.5
s = 199.5 - 168
s = 31.5 degrees  </PRE>