Penguins 41161

There were 10 more reindeer than penguins in the ice kingdom. But the lousy witch captured a third of the reindeer. There were only 22 reindeer left in the kingdom. How many penguins lived in the ice kingdom before the evil witch came?

Correct answer:

t =  23

Step-by-step explanation:

$$\begin{gathered} s=10+t \\ s-s/3=22 \\ s-t=10 \\ 2s=66 \\ Pivot:Row1\leftrightarrow Row2 \\ 2s=66 \\ s-t=10 \\ Row2-\frac{1}{2}\cdot Row1\to Row2 \\ 2s=66 \\ -t=-23 \\ t=\frac{-23}{-1}=23 \\ s=\frac{66}{2}=33 \\ s=33 \\ t=23 \end{gathered}$$

Try another example