A coffee's temperature changed by -54°F in =
[tex] = 22\frac{1}{2} \: minutes[/tex]
The temperature change in the coffee each minute :-
[tex] = - 54 \div 22\frac{1}{2} [/tex]
[tex] = - 54 \div \frac{(2 \times 22 + 1)}{2} [/tex]
[tex] = - 54 \div \frac{45}{2} [/tex]
[tex] = - 54 \times \frac{2}{45} [/tex]
[tex] = \frac{ (- 54 \times 2)}{ \: \: 45} [/tex]
[tex] = \frac{ - 108}{ \: \: \: 45} [/tex]
[tex]\color{magenta} = - 2.4°F[/tex]
Therefore , the temperature change in the coffee each minute was = -2.4°F .
