Question

The average temperature of the first three days of a week is 27${}^o$C and the next three days is 29${}^o$C. If the weekly average is 28.5${}^o$C. What is the temperature on the last day?

• A. 31.5${}^o$C
• B. 28${}^o$C
• C. 21${}^o$C
• D. 42${}^o$C

Answer 1

The correct option is A 31.5${}^o$C

Mean temperature would be given by:

$\frac{27\times 3+29\times 3+TemperatureofLastDay}{7}=28.5$

$\therefore 28.5\times 7-27\times 3-29\times 3={31.5}^{o}C$