The average temperature of the first three days is 27∘C and that of the next three days is 29∘C. If the average of the whole week is 28.5∘C, the temperature of the last day of the week is :	Choose the correct choice from the following choices
A) 10.5∘C B) 21∘C C) 31.5∘C D) 42∘C E) None
Explanation:   Let the seventh day temperature be x. Then total temperature for the whole week is   3×27+3×29+1×x=7×28.5   x = 31.5   31.5∘Correct Option: 31.5∘C
<result>C</result>
The average temperature of the first three days is 27∘C and that of the next three days is 29∘C. If the average of the whole week is 28.5∘C, the temperature of the last day of the week is :