Jack have to cut 11 boards.
Solution:
Given that , out of the 52 boards jack used to build the deck, 20% of them had to be cut.
We have to find how many boards did he have to cut
Now, we know that, he have to cut 20% of 52 boards
[tex]\begin{array}{l}{\rightarrow \text { number of boards to be cut }=20 \% \times 52} \\\\ {20 \% \text { can be written in fraction as } \frac{20}{100}} \\\\ {\rightarrow \text { number of boards to be cut }=\frac{20}{100} \times 52=\frac{1}{5} \times 52=10.4}\end{array}[/tex]
Here, 0.4 represents not fully cut board, but still that board is cut and treated as cut board.
Hence, jack have to cut 11 boards.
