Question

The average temperature for the first four days of the week was ${39}^o$C. The average of the whole week was ${40}^o$C. What was the average temperature during the last three days of the week?

Answer 1

Sum of Temperature of first 4 days $=39\ast 4=156$

Now, Sum of Temperature of whole week $=40\ast 7=280$

So, Sum of Temperature of last 3 days is $=280-156=124$

So, Average of last temperature is $=\frac{124}{3}={41.34}^o$