We were given the following information:
A cup of hot water is left out to cool
The water is currently 70 Degrees
Heat difference decreases by 5% every minute = 5% = 5/100 = 0.05
In 15 minutes, the temperature of the water is given by:
[tex]\begin{gathered} T_{}=70-0.05x \\ when\colon x=15 \\ T=70-0.05(15) \\ T=70-0.75 \\ T=69.25\approx69.3 \\ \\ \therefore T=69.3(to\text{ the nearest tenth)} \end{gathered}[/tex]