## 'Highs and Lows' printed from http://nrich.maths.org/

I have a max/min thermometer in my greenhouse. It records both the highest and the lowest temperatures reached from the time I reset it. I reset it on Sunday when the temperature was $4^\circ \text{C}$. Overnight the temperature fell $5^\circ$. Then during Monday it rose by $6^\circ$ before falling $10^\circ$ during the night. On Tuesday it rose by $4^\circ$ and fell by $2^\circ$ overnight. On Wednesday morning, what were the maximum and minimum temperatures recorded?