Pat and Mat dug a well. On the first day, Pat dug a hole $40 \mathrm{~cm}$ deep. The second day, Mat continued and dug to three times the depth. On the third day, Pat dug as much as Mat did the previous day and hit water. At that moment, the ground was $50 \mathrm{~cm}$ above the top of his head.

Determine how tall Pat was.

(M. Dillingerová)
On the first day, Pat dug $40 \mathrm{~cm}$.

On the second day, Mat dug to $3 \cdot 40=120(\mathrm{~cm})$, so he dug $120-40=80(\mathrm{~cm})$.

On the third day, Pat also dug $80 \mathrm{~cm}$, reaching a depth of $120+80=200(\mathrm{~cm})$. At that moment, the hole was $50 \mathrm{~cm}$ deeper than Pat, so Pat measured $200-50=150(\mathrm{~cm})$.

Scoring suggestion. 2 points for the depth of the hole on the second day; 3 points for the depth of the hole on the third day; 1 point for Pat's height.